Climate and average weather in Santa Helena
In Santa Helena, the summers are muggy, hot, wet, and partly cloudy and the winters are warm and partly cloudy.
Over the course of the year, the temperature in Santa Helena typically varies from 14°C to 31°C, and is rarely below 7°C or above 34°C. January is the hottest month of the year, while June is the coldest.
Based on the travel score, the best time of year to visit Santa Helena for warm-weather activities is from mid April to late September.
- Hottest
- Jan
- 31°
- Coldest
- Jun
- 15°
- Wettest
- Oct
- 162 mm
- Driest
- Aug
- 85 mm
- Rain / yr
- 1478 mm
- 130 wet days
- Daylight
- 10.5–13.5 h
- shortest–longest
- Elevation
- 254 m
- 24.9°S
- Clearest
- Aug
- 40% cloud
Santa Helena weather by month, at a glance
The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.
Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around mid April to late September.
Temperature through the year
Daily average highs and lows in Santa Helena, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
The hot season lasts 5.6 months, from October 19 to April 5, with daily high temperatures above 29°C. The hottest month of the year in Santa Helena is January, with an average high of 31°C and low of 23°C.
The cool season lasts 2.7 months, from May 14 to August 3, with daily high temperatures below 24°C. The coldest month of the year in Santa Helena is June, with an average low of 15°C and high of 23°C.
Days typically run about 9°C warmer than nights year-round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 31 | 31 | 30 | 28 | 24 | 23 | 23 | 25 | 27 | 29 | 30 | 31 |
| Avg low (°C) | 23 | 23 | 22 | 19 | 16 | 15 | 14 | 15 | 17 | 20 | 21 | 22 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 31 | 23 |
| Feb | 31 | 23 |
| Mar | 30 | 22 |
| Apr | 28 | 19 |
| May | 24 | 16 |
| Jun | 23 | 15 |
| Jul | 23 | 14 |
| Aug | 25 | 15 |
| Sep | 27 | 17 |
| Oct | 29 | 20 |
| Nov | 30 | 21 |
| Dec | 31 | 22 |
How hot and cold Santa Helena really feels
The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.
On the hottest afternoons, once humidity is folded in, Santa Helena feels like about 34°C (around January 26). About 111 days a year carry some heat stress, peaking in January.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels-like high (°C) | 34 | 34 | 33 | 29 | 24 | 23 | 23 | 25 | 27 | 30 | 31 | 33 |
| Air high (°C) | 31 | 31 | 30 | 28 | 24 | 23 | 23 | 25 | 27 | 29 | 30 | 31 |
| Feels-like low (°C) | 23 | 22 | 22 | 19 | 16 | 15 | 14 | 15 | 17 | 19 | 20 | 22 |
| Air low (°C) | 23 | 23 | 22 | 19 | 16 | 15 | 14 | 15 | 17 | 20 | 21 | 22 |
| Feels-like high (°C) | Air high (°C) | Feels-like low (°C) | Air low (°C) | |
|---|---|---|---|---|
| Jan | 34 | 31 | 23 | 23 |
| Feb | 34 | 31 | 22 | 23 |
| Mar | 33 | 30 | 22 | 22 |
| Apr | 29 | 28 | 19 | 19 |
| May | 24 | 24 | 16 | 16 |
| Jun | 23 | 23 | 15 | 15 |
| Jul | 23 | 23 | 14 | 14 |
| Aug | 25 | 25 | 15 | 15 |
| Sep | 27 | 27 | 17 | 17 |
| Oct | 30 | 29 | 19 | 20 |
| Nov | 31 | 30 | 20 | 21 |
| Dec | 33 | 31 | 22 | 22 |
Average hourly temperature in Santa Helena
A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on January afternoons, near 31°C, and coldest before dawn in June, near 15°C.
Santa Helena weather by month
Every month at a glance. Click a month for its detailed page.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 31° / 23° | 128 | 15.2 | 13.4 | 3.9 |
| Feb | 31° / 23° | 125 | 13.8 | 12.9 | 4.0 |
| Mar | 30° / 22° | 101 | 12 | 12.2 | 4.7 |
| Apr | 28° / 19° | 106 | 8.4 | 11.4 | 6.3 |
| May | 24° / 16° | 139 | 9.1 | 10.8 | 7.1 |
| Jun | 23° / 15° | 114 | 8.8 | 10.5 | 7.1 |
| Jul | 23° / 14° | 99 | 7.9 | 10.6 | 7.4 |
| Aug | 25° / 15° | 85 | 6.5 | 11.1 | 7.7 |
| Sep | 27° / 17° | 133 | 9.2 | 11.8 | 6.8 |
| Oct | 29° / 20° | 162 | 12.6 | 12.6 | 5.3 |
| Nov | 30° / 21° | 133 | 11.6 | 13.2 | 4.9 |
| Dec | 31° / 22° | 154 | 14.4 | 13.5 | 4.2 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Santa Helena gets about 1478 mm of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.
The wetter season lasts 6.0 months, from around Sep 24 to Mar 24, peaking in February at about 51% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Aug 23.
October is the wettest month by volume, with 162 mm over about 13 wet days; August is the driest, with 85 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 49 | 49 | 39 | 28 | 29 | 29 | 26 | 22 | 30 | 41 | 39 | 45 |
| Rain days | 15 | 14 | 12 | 8 | 9 | 9 | 8 | 7 | 9 | 13 | 12 | 14 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 49 | 15 |
| Feb | 49 | 14 |
| Mar | 39 | 12 |
| Apr | 28 | 8 |
| May | 29 | 9 |
| Jun | 29 | 9 |
| Jul | 26 | 8 |
| Aug | 22 | 7 |
| Sep | 30 | 9 |
| Oct | 41 | 13 |
| Nov | 39 | 12 |
| Dec | 45 | 14 |
Monthly rainfall
Over a full year, Santa Helena collects about 1478 mm of rain across 130 wet days — roughly 123 mm in an average month.
It doesn’t fall evenly. October is the wettest month with 162 mm, while August is the driest at just 85 mm. The three wettest months alone bring about 31% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 128 | 125 | 101 | 106 | 139 | 114 | 99 | 85 | 133 | 162 | 133 | 154 |
| Rain days | 15 | 14 | 12 | 8 | 9 | 9 | 8 | 7 | 9 | 13 | 12 | 14 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 128 | 15 |
| Feb | 125 | 14 |
| Mar | 101 | 12 |
| Apr | 106 | 8 |
| May | 139 | 9 |
| Jun | 114 | 9 |
| Jul | 99 | 8 |
| Aug | 85 | 7 |
| Sep | 133 | 9 |
| Oct | 162 | 13 |
| Nov | 133 | 12 |
| Dec | 154 | 14 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Santa Helena, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.
The clearer part of the year begins around July 2 and lasts for 2.7 months, ending around September 22. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 65% of the time on average.
The cloudier part of the year begins around September 23 and lasts for 5.3 months, ending around March 2. The cloudiest month is October, when it is overcast or mostly cloudy 54% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 50 | 53 | 58 | 58 | 52 | 54 | 61 | 65 | 59 | 46 | 51 | 50 |
| Cloudier (%) | 50 | 47 | 42 | 42 | 48 | 46 | 39 | 35 | 41 | 54 | 49 | 50 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 50 | 50 |
| Feb | 53 | 47 |
| Mar | 58 | 42 |
| Apr | 58 | 42 |
| May | 52 | 48 |
| Jun | 54 | 46 |
| Jul | 61 | 39 |
| Aug | 65 | 35 |
| Sep | 59 | 41 |
| Oct | 46 | 54 |
| Nov | 51 | 49 |
| Dec | 50 | 50 |
Daylight, sunrise and sunset
Hours of daylight through the year, with sunrise and sunset times.
The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around January 1, brings about 13 h 30 min of light; the shortest, around June 4, only 10 h 30 min — a swing of roughly 3 hours.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 13.4 | 12.9 | 12.2 | 11.4 | 10.8 | 10.5 | 10.6 | 11.1 | 11.8 | 12.6 | 13.2 | 13.5 |
| Sunrise (AM) | 7:05 | 7:26 | 7:42 | 7:55 | 8:10 | 8:24 | 8:25 | 8:08 | 7:36 | 7:05 | 6:46 | 6:47 |
| Sunset (PM) | 8:28 | 8:18 | 7:52 | 7:20 | 6:57 | 6:52 | 7:01 | 7:15 | 7:27 | 7:40 | 7:59 | 8:20 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 13.4 | 7:05 | 8:28 |
| Feb | 12.9 | 7:26 | 8:18 |
| Mar | 12.2 | 7:42 | 7:52 |
| Apr | 11.4 | 7:55 | 7:20 |
| May | 10.8 | 8:10 | 6:57 |
| Jun | 10.5 | 8:24 | 6:52 |
| Jul | 10.6 | 8:25 | 7:01 |
| Aug | 11.1 | 8:08 | 7:15 |
| Sep | 11.8 | 7:36 | 7:27 |
| Oct | 12.6 | 7:05 | 7:40 |
| Nov | 13.2 | 6:46 | 7:59 |
| Dec | 13.5 | 6:47 | 8:20 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Santa Helena averages about 12 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 9 and 18 days.
The sunnier stretch runs 3.7 months, from around Jun 5 to Sep 25. The sunniest month is August, with roughly 17 sunny days (bright).
The greyest month is February, down near 10 sunny days — about 39% fewer than the August peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 10 | 9 | 13 | 13 | 12 | 13 | 15 | 17 | 14 | 10 | 11 | 10 |
| Sky | Mixed | Mixed | Mixed | Mixed | Mixed | Mixed | Mixed | Bright | Mixed | Mixed | Mixed | Mixed |
| Sunny days | Sky | |
|---|---|---|
| Jan | 10 | Mixed |
| Feb | 9 | Mixed |
| Mar | 13 | Mixed |
| Apr | 13 | Mixed |
| May | 12 | Mixed |
| Jun | 13 | Mixed |
| Jul | 15 | Mixed |
| Aug | 17 | Bright |
| Sep | 14 | Mixed |
| Oct | 10 | Mixed |
| Nov | 11 | Mixed |
| Dec | 10 | Mixed |
Humidity comfort
Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.
Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.
In Santa Helena, how humid it feels changes dramatically over the year.
The more humid part of the year lasts 6.9 months, from around October 5 to May 2. The muggiest month is January, when the air feels humid, muggy or worse about 99% of the time.
The most comfortable stretch runs from around May 3 to October 4, and July is the most comfortable month — the air is dry or comfortable 71% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 0 | 0 | 0 | 6 | 20 | 27 | 37 | 35 | 23 | 6 | 3 | 0 |
| Comfortable (%) | 1 | 1 | 2 | 10 | 24 | 30 | 34 | 37 | 28 | 15 | 11 | 3 |
| Humid (%) | 5 | 7 | 13 | 25 | 34 | 35 | 26 | 25 | 33 | 26 | 24 | 12 |
| Muggy (%) | 27 | 29 | 40 | 43 | 20 | 8 | 3 | 3 | 16 | 44 | 42 | 36 |
| Oppressive (%) | 66 | 62 | 45 | 16 | 2 | 0 | 0 | 0 | 0 | 9 | 21 | 48 |
| Miserable (%) | 2 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| Jan | 0 | 1 | 5 | 27 | 66 | 2 |
| Feb | 0 | 1 | 7 | 29 | 62 | 1 |
| Mar | 0 | 2 | 13 | 40 | 45 | 0 |
| Apr | 6 | 10 | 25 | 43 | 16 | 0 |
| May | 20 | 24 | 34 | 20 | 2 | 0 |
| Jun | 27 | 30 | 35 | 8 | 0 | 0 |
| Jul | 37 | 34 | 26 | 3 | 0 | 0 |
| Aug | 35 | 37 | 25 | 3 | 0 | 0 |
| Sep | 23 | 28 | 33 | 16 | 0 | 0 |
| Oct | 6 | 15 | 26 | 44 | 9 | 0 |
| Nov | 3 | 11 | 24 | 42 | 21 | 0 |
| Dec | 0 | 3 | 12 | 36 | 48 | 1 |
Wind
Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.
This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.
Across the year, average wind speed in Santa Helena is typically calm, near 10 km/h, and varies little with the seasons.
The windier part of the year lasts 5.7 months, from around May 19 to Nov 9. The windiest month is August, averaging about 12 km/h (light breeze).
The calmer part of the year runs from around Nov 10 to May 18, with March the calmest month at about 9 km/h.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 9 | 9 | 9 | 10 | 10 | 11 | 12 | 12 | 12 | 11 | 10 | 10 |
| Feels | calm | calm | calm | calm | calm | calm | calm | light breeze | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 9 | calm |
| Feb | 9 | calm |
| Mar | 9 | calm |
| Apr | 10 | calm |
| May | 10 | calm |
| Jun | 11 | calm |
| Jul | 12 | calm |
| Aug | 12 | light breeze |
| Sep | 12 | calm |
| Oct | 11 | calm |
| Nov | 10 | calm |
| Dec | 10 | calm |
Best time to visit Santa Helena
To characterize how pleasant the weather is in Santa Helena throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around late April, Santa Helena is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.
Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.
The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Santa Helena for general outdoor tourist activities is from mid April to late September, with a peak score in the first week of August.
The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Travel score (0–10) | 3.9 | 4.0 | 4.8 | 6.3 | 7.1 | 7.1 | 7.4 | 7.6 | 6.8 | 5.3 | 4.9 | 4.2 |
| Rating | fair | fair | fair | good | good | good | good | ideal | good | fair | fair | fair |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 3.9 | fair |
| Feb | 4.0 | fair |
| Mar | 4.8 | fair |
| Apr | 6.3 | good |
| May | 7.1 | good |
| Jun | 7.1 | good |
| Jul | 7.4 | good |
| Aug | 7.6 | ideal |
| Sep | 6.8 | good |
| Oct | 5.3 | fair |
| Nov | 4.9 | fair |
| Dec | 4.2 | fair |
The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best times of year to visit Santa Helena for hot-weather activities run from late January to mid May and again from late July to late December, with a peak score in the last week of August.
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
What to pack for Santa Helena, by month
Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.
For a warm-season trip around January (highs near 31°C), the essentials are light clothes, rain gear and sun protection. In the cold season around June (highs near 23°C), pack light clothes and rain gear.
In January, Santa Helena sees daytime highs around 31°C and nights near 23°C. Pack light clothes, rain gear and sun protection. About 15 days see rain.
UV index (midday) in Santa Helena by month
Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.
Under clear skies, the midday UV index in Santa Helena peaks around January 19 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 11 at about 5 (high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 15 | 14 | 12 | 9 | 6 | 5 | 5 | 7 | 6 | 10 | 12 | 13 |
| Level | Extreme | Extreme | Extreme | Very high | High | High | Moderate | High | High | Very high | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 15 | Extreme |
| Feb | 14 | Extreme |
| Mar | 12 | Extreme |
| Apr | 9 | Very high |
| May | 6 | High |
| Jun | 5 | High |
| Jul | 5 | Moderate |
| Aug | 7 | High |
| Sep | 6 | High |
| Oct | 10 | Very high |
| Nov | 12 | Extreme |
| Dec | 13 | Extreme |
Average hourly UV index in Santa Helena
Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.
The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
UV falls off far faster than brightness as the sun drops, so even in January the burn window is concentrated in the middle of the day: about 9 hours a day reach index 3 (protection recommended), and 7.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 9 | 8.5 | 8 | 6.5 | 5.5 | 4.5 | 5 | 6 | 6 | 7.5 | 8.5 | 9 |
| UV ≥ 6 (h/day) | 7.5 | 6.5 | 6 | 4.5 | 1.5 | 0 | 0 | 2 | 1 | 5 | 6 | 7 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 9 | 7.5 |
| Feb | 8.5 | 6.5 |
| Mar | 8 | 6 |
| Apr | 6.5 | 4.5 |
| May | 5.5 | 1.5 |
| Jun | 4.5 | 0 |
| Jul | 5 | 0 |
| Aug | 6 | 2 |
| Sep | 6 | 1 |
| Oct | 7.5 | 5 |
| Nov | 8.5 | 6 |
| Dec | 9 | 7 |
Air quality in Santa Helena by month
Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.
Air quality in Santa Helena is worst in September — around 21 µg/m³ PM2.5 (moderate), about 3.6× the cleanest month (March, 6 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 7 | 6 | 6 | 7 | 7 | 8 | 7 | 12 | 21 | 12 | 8 | 7 |
| Level | Good | Good | Good | Good | Good | Good | Good | Moderate | Moderate | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 7 | Good |
| Feb | 6 | Good |
| Mar | 6 | Good |
| Apr | 7 | Good |
| May | 7 | Good |
| Jun | 8 | Good |
| Jul | 7 | Good |
| Aug | 12 | Moderate |
| Sep | 21 | Moderate |
| Oct | 12 | Good |
| Nov | 8 | Good |
| Dec | 7 | Good |
Growing season
Santa Helena is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frost-free chance (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Frost nights | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Frost-free chance (%) | Frost nights | |
|---|---|---|
| Jan | 100 | 0 |
| Feb | 100 | 0 |
| Mar | 100 | 0 |
| Apr | 100 | 0 |
| May | 100 | 0 |
| Jun | 100 | 0 |
| Jul | 100 | 0 |
| Aug | 100 | 0 |
| Sep | 100 | 0 |
| Oct | 100 | 0 |
| Nov | 100 | 0 |
| Dec | 100 | 0 |
Growing degree days
Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Santa Helena banks about 4,826 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around January.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Growing degree days (°C·days) | 524 | 467 | 496 | 411 | 314 | 267 | 262 | 321 | 366 | 438 | 454 | 507 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 524 |
| Feb | 467 |
| Mar | 496 |
| Apr | 411 |
| May | 314 |
| Jun | 267 |
| Jul | 262 |
| Aug | 321 |
| Sep | 366 |
| Oct | 438 |
| Nov | 454 |
| Dec | 507 |
Solar energy
Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.
Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.
Santa Helena receives about 4.9 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.0 and 6.4 kWh/m².
The brighter stretch of the year lasts 6.6 months, from around Sep 11 to Mar 30. The brightest month is December, averaging about 6.4 kWh/m² (intense).
The dimmest month is June, down near 3.0 kWh/m² — roughly 53% less than the December peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 6.3 | 5.8 | 5.3 | 4.4 | 3.4 | 3.0 | 3.3 | 4.2 | 4.9 | 5.5 | 6.2 | 6.4 |
| Level | Intense | Bright | Bright | Bright | Moderate | Moderate | Moderate | Bright | Bright | Bright | Intense | Intense |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 6.3 | Intense |
| Feb | 5.8 | Bright |
| Mar | 5.3 | Bright |
| Apr | 4.4 | Bright |
| May | 3.4 | Moderate |
| Jun | 3.0 | Moderate |
| Jul | 3.3 | Moderate |
| Aug | 4.2 | Bright |
| Sep | 4.9 | Bright |
| Oct | 5.5 | Bright |
| Nov | 6.2 | Intense |
| Dec | 6.4 | Intense |
Where is Santa Helena?
Santa Helena sits at 24.9°S, 54.3°W, 254 m above sea level, in Brazil. The nearest listed city is Marechal Cândido Rondon, 44 km away.
Topography around Santa Helena
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Santa Helena.
Within 3 km, the terrain around Santa Helena has only modest variations in elevation — a maximum elevation change of 72 m around an average of 238 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 259 m; within 80 km, large variations in elevation — a maximum elevation change of 674 m.
The land around Santa Helena is covered by cropland (31%), trees (30%) and water (20%) within 3 km, trees (33%), cropland (31%) and water (28%) within 16 km, and cropland (57%) and trees (28%) within 80 km.
Brazil travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type C / N
- 127 / 220 V · 60 Hz
- Prices
- ≈ 46% of US
- price level, 2025
- GDP per capita
- $10,713
- 2025
- Happiness
- 6.6 / 10
- World Happiness, 2025
- Safe drinking water
- 89%
- of population, 2024
- Homicide rate
- 19.3
- per 100k, 2023
- Road deaths
- 16
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Low
- EF EPI 482
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Santa Helena (-24.8603°, -54.3328°, elevation 254 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).