Saint Helena weather by month
Average temperatures and rainfall across Saint Helena, based on 30 years of climate data.
The average temperature in Saint Helena is around 21° across the year, though it swings month to month and from region to region. The figures below show the monthly pattern for Jamestown.
- Hottest
- Mar
- 24°
- Coldest
- Sep
- 19°
- Wettest
- Mar
- 5 mm
- Driest
- Oct
- 1 mm
- Annual avg
- 21°
- year-round
- Rain / yr
- 28 mm
- 6 wet days
- Largest city
- Jamestown
- 1k people
- Cities
- 1
- with climate data
Monthly climate (Jamestown)
Average highs, lows and rainfall through the year for Jamestown, Saint Helena's largest city.
| Month | High / Low | Rainfall | Wet days |
|---|---|---|---|
| Jan | 23° / 22° | 2 mm | 0.4 |
| Feb | 24° / 23° | 3 mm | 0.6 |
| Mar | 24° / 24° | 5 mm | 1.4 |
| Apr | 24° / 23° | 3 mm | 0.6 |
| May | 23° / 22° | 4 mm | 1.1 |
| Jun | 22° / 21° | 5 mm | 1.1 |
| Jul | 21° / 20° | 3 mm | 0.5 |
| Aug | 20° / 19° | 2 mm | 0.3 |
| Sep | 20° / 19° | 1 mm | 0.1 |
| Oct | 20° / 19° | 1 mm | 0.1 |
| Nov | 20° / 20° | 1 mm | 0 |
| Dec | 21° / 21° | 1 mm | 0 |
Climate in Jamestown
Full Jamestown forecastJamestown is the largest city in Saint Helena; its cloud cover, humidity, wind and sunshine are typical of the surrounding region.
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast through the year.
In Jamestown, 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 November 23 and lasts for 6.2 months, ending around May 31. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 87% of the time on average.
The cloudier part of the year begins around June 1 and lasts for 5.7 months, ending around November 22. The cloudiest month is September, when it is overcast or mostly cloudy 72% of the time.
Humidity comfort
Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.
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 Jamestown is typically breezy, near 26 km/h, and varies moderately with the seasons.
The windier part of the year lasts 5.9 months, from around May 30 to Nov 25. The windiest month is August, averaging about 28 km/h (breezy).
The calmer part of the year runs from around Nov 26 to May 29, with January the calmest month at about 24 km/h.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 24 | 23 | 25 | 25 | 25 | 26 | 27 | 28 | 28 | 28 | 26 | 24 |
| Feels | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy | breezy |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 24 | breezy |
| Feb | 23 | breezy |
| Mar | 25 | breezy |
| Apr | 25 | breezy |
| May | 25 | breezy |
| Jun | 26 | breezy |
| Jul | 27 | breezy |
| Aug | 28 | breezy |
| Sep | 28 | breezy |
| Oct | 28 | breezy |
| Nov | 26 | breezy |
| Dec | 24 | breezy |
Best time to visit Saint Helena
A 0–10 score combining daytime comfort, chance of rain and cloud cover — the sweet spot runs early January to late December.
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.
Jamestown receives about 5.6 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.8 and 7.1 kWh/m².
The brighter stretch of the year lasts 6.3 months, from around Sep 30 to Apr 9. The brightest month is January, averaging about 7.1 kWh/m² (intense).
The dimmest month is June, down near 3.9 kWh/m² — roughly 45% less than the January peak.
Where is Saint Helena?
Saint Helena sits around 15.9°S, 5.7°W. The marker shows Jamestown, its largest city, among 1 city with climate data here.
Saint Helena travel facts
- Power plugs
- Type G
- 230 V · 50 Hz
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.