Climate and average weather in Santa Rosa
In Santa Rosa, the summers are humid, hot, wet, and partly cloudy and the winters are mild and partly cloudy.
Over the course of the year, the temperature in Santa Rosa typically varies from 9°C to 31°C, and is rarely below 3°C or above 38°C. December 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 Rosa for warm-weather activities is from late June to late September.
- Hottest
- Dec
- 31°
- Coldest
- Jun
- 11°
- Wettest
- Mar
- 249 mm
- Driest
- Aug
- 16 mm
- Rain / yr
- 1467 mm
- 136 wet days
- Daylight
- 10.6–13.4 h
- shortest–longest
- Elevation
- 341 m
- 23.4°S
- Clearest
- Aug
- 34% cloud
Santa Rosa 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 late June to late September.
Temperature through the year
Daily average highs and lows in Santa Rosa, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
The hot season lasts 5.2 months, from September 27 to March 3, with daily high temperatures above 29°C. The hottest month of the year in Santa Rosa is December, with an average high of 31°C and low of 21°C.
The cool season lasts 2.7 months, from May 11 to July 31, with daily high temperatures below 22°C. The coldest month of the year in Santa Rosa is June, with an average low of 11°C and high of 20°C.
Days typically run about 10°C warmer than nights, with the widest day–night swing (around 14°C) in September.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 31 | 30 | 28 | 25 | 22 | 20 | 21 | 25 | 28 | 30 | 31 | 31 |
| Avg low (°C) | 22 | 21 | 20 | 17 | 14 | 11 | 9 | 11 | 15 | 18 | 20 | 21 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 31 | 22 |
| Feb | 30 | 21 |
| Mar | 28 | 20 |
| Apr | 25 | 17 |
| May | 22 | 14 |
| Jun | 20 | 11 |
| Jul | 21 | 9 |
| Aug | 25 | 11 |
| Sep | 28 | 15 |
| Oct | 30 | 18 |
| Nov | 31 | 20 |
| Dec | 31 | 21 |
How hot and cold Santa Rosa 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 Rosa feels like about 34°C (around January 1). About 66 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) | 33 | 32 | 29 | 25 | 22 | 20 | 21 | 25 | 28 | 30 | 31 | 33 |
| Air high (°C) | 31 | 30 | 28 | 25 | 22 | 20 | 21 | 25 | 28 | 30 | 31 | 31 |
| Feels-like low (°C) | 21 | 21 | 20 | 17 | 14 | 11 | 9 | 11 | 15 | 18 | 20 | 21 |
| Air low (°C) | 22 | 21 | 20 | 17 | 14 | 11 | 9 | 11 | 15 | 18 | 20 | 21 |
| Feels-like high (°C) | Air high (°C) | Feels-like low (°C) | Air low (°C) | |
|---|---|---|---|---|
| Jan | 33 | 31 | 21 | 22 |
| Feb | 32 | 30 | 21 | 21 |
| Mar | 29 | 28 | 20 | 20 |
| Apr | 25 | 25 | 17 | 17 |
| May | 22 | 22 | 14 | 14 |
| Jun | 20 | 20 | 11 | 11 |
| Jul | 21 | 21 | 9 | 9 |
| Aug | 25 | 25 | 11 | 11 |
| Sep | 28 | 28 | 15 | 15 |
| Oct | 30 | 30 | 18 | 18 |
| Nov | 31 | 31 | 20 | 20 |
| Dec | 33 | 31 | 21 | 21 |
Average hourly temperature in Santa Rosa
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 December afternoons, near 31°C, and coldest before dawn in June, near 11°C.
Santa Rosa 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° / 22° | 224 | 16.5 | 13.3 | 3.7 |
| Feb | 30° / 21° | 228 | 16.2 | 12.8 | 4.1 |
| Mar | 28° / 20° | 249 | 18.1 | 12.2 | 4.8 |
| Apr | 25° / 17° | 162 | 15.3 | 11.5 | 5.9 |
| May | 22° / 14° | 79 | 11.9 | 10.9 | 6.3 |
| Jun | 20° / 11° | 38 | 7.9 | 10.6 | 6.6 |
| Jul | 21° / 9° | 23 | 5.1 | 10.7 | 7.5 |
| Aug | 25° / 11° | 16 | 3.6 | 11.2 | 8.3 |
| Sep | 28° / 15° | 22 | 4.3 | 11.9 | 7.1 |
| Oct | 30° / 18° | 81 | 9.5 | 12.5 | 5.0 |
| Nov | 31° / 20° | 126 | 11.9 | 13.1 | 4.3 |
| Dec | 31° / 21° | 218 | 15.4 | 13.4 | 3.7 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Santa Rosa gets about 1467 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 6.3 months, from around Nov 10 to May 19, peaking in March at about 60% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Aug 23.
March is the wettest month by volume, with 249 mm over about 18 wet days; August is the driest, with 16 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 54 | 58 | 59 | 50 | 38 | 28 | 16 | 12 | 14 | 30 | 40 | 49 |
| Rain days | 17 | 16 | 18 | 15 | 12 | 8 | 5 | 4 | 4 | 10 | 12 | 15 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 54 | 17 |
| Feb | 58 | 16 |
| Mar | 59 | 18 |
| Apr | 50 | 15 |
| May | 38 | 12 |
| Jun | 28 | 8 |
| Jul | 16 | 5 |
| Aug | 12 | 4 |
| Sep | 14 | 4 |
| Oct | 30 | 10 |
| Nov | 40 | 12 |
| Dec | 49 | 15 |
Monthly rainfall
Over a full year, Santa Rosa collects about 1467 mm of rain across 136 wet days — roughly 122 mm in an average month.
It doesn’t fall evenly. March is the wettest month with 249 mm, while August is the driest at just 16 mm. The three wettest months alone bring about 48% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 224 | 228 | 249 | 162 | 79 | 38 | 23 | 16 | 22 | 81 | 126 | 218 |
| Rain days | 17 | 16 | 18 | 15 | 12 | 8 | 5 | 4 | 4 | 10 | 12 | 15 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 224 | 17 |
| Feb | 228 | 16 |
| Mar | 249 | 18 |
| Apr | 162 | 15 |
| May | 79 | 12 |
| Jun | 38 | 8 |
| Jul | 23 | 5 |
| Aug | 16 | 4 |
| Sep | 22 | 4 |
| Oct | 81 | 10 |
| Nov | 126 | 12 |
| Dec | 218 | 15 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Santa Rosa, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.
The clearer part of the year begins around June 17 and lasts for 4.2 months, ending around October 22. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 72% of the time on average.
The cloudier part of the year begins around November 7 and lasts for 7.3 months, ending around June 16. The cloudiest month is March, when it is overcast or mostly cloudy 68% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 33 | 33 | 32 | 34 | 38 | 46 | 63 | 72 | 67 | 49 | 42 | 34 |
| Cloudier (%) | 67 | 67 | 68 | 66 | 62 | 54 | 37 | 28 | 33 | 51 | 58 | 66 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 33 | 67 |
| Feb | 33 | 67 |
| Mar | 32 | 68 |
| Apr | 34 | 66 |
| May | 38 | 62 |
| Jun | 46 | 54 |
| Jul | 63 | 37 |
| Aug | 72 | 28 |
| Sep | 67 | 33 |
| Oct | 49 | 51 |
| Nov | 42 | 58 |
| Dec | 34 | 66 |
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 24 min of light; the shortest, around June 3, only 10 h 36 min — a swing of roughly 2 h 48 min.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 13.3 | 12.8 | 12.2 | 11.5 | 10.9 | 10.6 | 10.7 | 11.2 | 11.9 | 12.5 | 13.1 | 13.4 |
| Sunrise (AM) | 6:48 | 7:08 | 7:22 | 7:34 | 7:48 | 8:01 | 8:03 | 7:46 | 7:16 | 6:46 | 6:29 | 6:31 |
| Sunset (PM) | 8:06 | 7:57 | 7:32 | 7:02 | 6:40 | 6:35 | 6:44 | 6:57 | 7:08 | 7:19 | 7:37 | 7:57 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 13.3 | 6:48 | 8:06 |
| Feb | 12.8 | 7:08 | 7:57 |
| Mar | 12.2 | 7:22 | 7:32 |
| Apr | 11.5 | 7:34 | 7:02 |
| May | 10.9 | 7:48 | 6:40 |
| Jun | 10.6 | 8:01 | 6:35 |
| Jul | 10.7 | 8:03 | 6:44 |
| Aug | 11.2 | 7:46 | 6:57 |
| Sep | 11.9 | 7:16 | 7:08 |
| Oct | 12.5 | 6:46 | 7:19 |
| Nov | 13.1 | 6:29 | 7:37 |
| Dec | 13.4 | 6:31 | 7:57 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Santa Rosa averages about 10 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 4 and 19 days.
The sunnier stretch runs 4.4 months, from around Jun 9 to Oct 19. The sunniest month is August, with roughly 19 sunny days (bright).
The greyest month is February, down near 4 sunny days — about 77% fewer than the August peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 5 | 4 | 5 | 6 | 9 | 11 | 16 | 19 | 16 | 11 | 8 | 6 |
| Sky | Gloomy | Gloomy | Gloomy | Gloomy | Mixed | Mixed | Bright | Bright | Bright | Mixed | Mixed | Gloomy |
| Sunny days | Sky | |
|---|---|---|
| Jan | 5 | Gloomy |
| Feb | 4 | Gloomy |
| Mar | 5 | Gloomy |
| Apr | 6 | Gloomy |
| May | 9 | Mixed |
| Jun | 11 | Mixed |
| Jul | 16 | Bright |
| Aug | 19 | Bright |
| Sep | 16 | Bright |
| Oct | 11 | Mixed |
| Nov | 8 | Mixed |
| Dec | 6 | Gloomy |
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 Rosa, how humid it feels changes dramatically over the year.
The more humid part of the year lasts 6.3 months, from around October 26 to May 5. The muggiest month is January, when the air feels humid, muggy or worse about 97% of the time.
The most comfortable stretch runs from around May 6 to October 25, and July is the most comfortable month — the air is dry or comfortable 95% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 0 | 0 | 1 | 11 | 38 | 62 | 77 | 79 | 69 | 34 | 16 | 3 |
| Comfortable (%) | 3 | 4 | 5 | 17 | 23 | 22 | 18 | 16 | 19 | 24 | 17 | 8 |
| Humid (%) | 14 | 14 | 19 | 29 | 26 | 15 | 5 | 5 | 11 | 28 | 28 | 19 |
| Muggy (%) | 38 | 39 | 42 | 31 | 12 | 2 | 0 | 0 | 1 | 13 | 31 | 39 |
| Oppressive (%) | 45 | 42 | 34 | 12 | 1 | 0 | 0 | 0 | 0 | 1 | 8 | 30 |
| Miserable (%) | 1 | 2 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| Jan | 0 | 3 | 14 | 38 | 45 | 1 |
| Feb | 0 | 4 | 14 | 39 | 42 | 2 |
| Mar | 1 | 5 | 19 | 42 | 34 | 1 |
| Apr | 11 | 17 | 29 | 31 | 12 | 0 |
| May | 38 | 23 | 26 | 12 | 1 | 0 |
| Jun | 62 | 22 | 15 | 2 | 0 | 0 |
| Jul | 77 | 18 | 5 | 0 | 0 | 0 |
| Aug | 79 | 16 | 5 | 0 | 0 | 0 |
| Sep | 69 | 19 | 11 | 1 | 0 | 0 |
| Oct | 34 | 24 | 28 | 13 | 1 | 0 |
| Nov | 16 | 17 | 28 | 31 | 8 | 0 |
| Dec | 3 | 8 | 19 | 39 | 30 | 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.
Wind in Santa Rosa is steady company: average speeds sit near 6 km/h — calm — in every month of the year, with no meaningful windy or calm season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 6 | 6 | 5 | 5 | 5 | 5 | 6 | 6 | 7 | 7 | 7 | 6 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 6 | calm |
| Feb | 6 | calm |
| Mar | 5 | calm |
| Apr | 5 | calm |
| May | 5 | calm |
| Jun | 5 | calm |
| Jul | 6 | calm |
| Aug | 6 | calm |
| Sep | 7 | calm |
| Oct | 7 | calm |
| Nov | 7 | calm |
| Dec | 6 | calm |
Hazard calendar for Santa Rosa
When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.
Santa Rosa's monsoon runs November–April, when most of the year's rain falls.
Best time to visit Santa Rosa
To characterize how pleasant the weather is in Santa Rosa throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around early July, Santa Rosa 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 Rosa for general outdoor tourist activities is from late June to late September, with a peak score in the third 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) | 3.7 | 4.1 | 4.8 | 5.9 | 6.3 | 6.6 | 7.5 | 8.3 | 7.1 | 5.0 | 4.3 | 3.7 |
| Rating | fair | fair | fair | good | good | good | ideal | ideal | good | fair | fair | fair |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 3.7 | fair |
| Feb | 4.1 | fair |
| Mar | 4.8 | fair |
| Apr | 5.9 | good |
| May | 6.3 | good |
| Jun | 6.6 | good |
| Jul | 7.5 | ideal |
| Aug | 8.3 | ideal |
| Sep | 7.1 | good |
| Oct | 5.0 | fair |
| Nov | 4.3 | fair |
| Dec | 3.7 | fair |
The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Santa Rosa for hot-weather activities is from early August to early November, with a peak score in the third week of September.
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 Rosa, 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 December (highs near 31°C), the essentials are light clothes, rain gear and sun protection. In the cold season around June (highs near 20°C), pack a light layer.
In December, Santa Rosa sees daytime highs around 31°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 15 days see rain.
UV index (midday) in Santa Rosa 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 Rosa peaks around January 18 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 | 13 | 9 | 7 | 6 | 5 | 8 | 10 | 8 | 13 | 14 |
| Level | Extreme | Extreme | Extreme | Very high | High | High | High | Very high | Very high | Very high | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 15 | Extreme |
| Feb | 14 | Extreme |
| Mar | 13 | Extreme |
| Apr | 9 | Very high |
| May | 7 | High |
| Jun | 6 | High |
| Jul | 5 | High |
| Aug | 8 | Very high |
| Sep | 10 | Very high |
| Oct | 8 | Very high |
| Nov | 13 | Extreme |
| Dec | 14 | Extreme |
Average hourly UV index in Santa Rosa
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 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 | 7 | 6 | 5 | 5 | 6 | 7 | 7.5 | 8.5 | 9 |
| UV ≥ 6 (h/day) | 7 | 7 | 6 | 4.5 | 2.5 | 0 | 0 | 3.5 | 5 | 4.5 | 6.5 | 7 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 9 | 7 |
| Feb | 8.5 | 7 |
| Mar | 8 | 6 |
| Apr | 7 | 4.5 |
| May | 6 | 2.5 |
| Jun | 5 | 0 |
| Jul | 5 | 0 |
| Aug | 6 | 3.5 |
| Sep | 7 | 5 |
| Oct | 7.5 | 4.5 |
| Nov | 8.5 | 6.5 |
| Dec | 9 | 7 |
Air quality in Santa Rosa 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 Rosa is worst in September — around 36 µg/m³ PM2.5 (poor), about 8.2× the cleanest month (May, 4 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) | 8 | 8 | 7 | 5 | 4 | 7 | 8 | 15 | 36 | 32 | 27 | 17 |
| Level | Good | Good | Good | Good | Good | Good | Good | Moderate | Poor | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 8 | Good |
| Feb | 8 | Good |
| Mar | 7 | Good |
| Apr | 5 | Good |
| May | 4 | Good |
| Jun | 7 | Good |
| Jul | 8 | Good |
| Aug | 15 | Moderate |
| Sep | 36 | Poor |
| Oct | 32 | Moderate |
| Nov | 27 | Moderate |
| Dec | 17 | Moderate |
Growing season
Santa Rosa 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 | 99 | 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 | 99 | 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 Rosa banks about 4,226 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) | 505 | 428 | 428 | 330 | 239 | 162 | 153 | 245 | 338 | 439 | 458 | 502 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 505 |
| Feb | 428 |
| Mar | 428 |
| Apr | 330 |
| May | 239 |
| Jun | 162 |
| Jul | 153 |
| Aug | 245 |
| Sep | 338 |
| Oct | 439 |
| Nov | 458 |
| Dec | 502 |
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 Rosa receives about 4.5 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 2.9 and 5.9 kWh/m².
The brighter stretch of the year lasts 6.7 months, from around Aug 15 to Mar 6. The brightest month is December, averaging about 5.7 kWh/m² (bright).
The dimmest month is May, down near 3.0 kWh/m² — roughly 48% less than the December peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.7 | 5.1 | 4.2 | 3.4 | 2.9 | 3.0 | 3.6 | 4.6 | 5.3 | 5.3 | 5.6 | 5.7 |
| Level | Bright | Bright | Bright | Moderate | Moderate | Moderate | Moderate | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 5.7 | Bright |
| Feb | 5.1 | Bright |
| Mar | 4.2 | Bright |
| Apr | 3.4 | Moderate |
| May | 2.9 | Moderate |
| Jun | 3.0 | Moderate |
| Jul | 3.6 | Moderate |
| Aug | 4.6 | Bright |
| Sep | 5.3 | Bright |
| Oct | 5.3 | Bright |
| Nov | 5.6 | Bright |
| Dec | 5.7 | Bright |
Where is Santa Rosa?
Santa Rosa sits at 23.4°S, 64.4°W, 341 m above sea level, in Argentina. The nearest listed city is Pichanal, 23 km away.
Topography around Santa Rosa
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Santa Rosa.
Within 3 km, the terrain around Santa Rosa has only modest variations in elevation — a maximum elevation change of 78 m around an average of 352 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 433 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,850 m.
The land around Santa Rosa is covered by cropland (43%) and trees (31%) within 3 km, trees (62%) and cropland (31%) within 16 km, and trees (64%) within 80 km.
Argentina travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type C / I
- 220 V · 50 Hz
- Prices
- ≈ 46% of US
- price level, 2025
- GDP per capita
- $14,898
- 2025
- Happiness
- 6.4 / 10
- World Happiness, 2025
- Homicide rate
- 4.5
- per 100k, 2023
- Road deaths
- 14.1
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- High
- EF EPI 575
- 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 Rosa (-23.3943°, -64.4251°, elevation 341 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).