Best time to visit Isles of Scilly
Month-by-month weather averages for Isles of Scilly.
Isles of Scilly, England, United Kingdom
°C
mm
- Average daily high and low
- Precipitation
- Good month
- Best month
- Made good or best by an event
| Month | Average daily high | Average daily low | Precipitation | Verdict |
|---|---|---|---|---|
| January | 10.3 °C / 51 °F | 8.5 °C / 47 °F | 89 mm / 3.5 in | neither best nor good |
| February | 9.9 °C / 50 °F | 8.2 °C / 47 °F | 73 mm / 2.9 in | neither best nor good |
| March | 9.9 °C / 50 °F | 8.3 °C / 47 °F | 66 mm / 2.6 in | neither best nor good |
| April | 10.8 °C / 51 °F | 9.5 °C / 49 °F | 48 mm / 1.9 in | neither best nor good |
| May | 12.7 °C / 55 °F | 11.5 °C / 53 °F | 49 mm / 1.9 in | good month |
| June | 15.1 °C / 59 °F | 14 °C / 57 °F | 48 mm / 1.9 in | good month |
| July | 17 °C / 63 °F | 15.9 °C / 61 °F | 55 mm / 2.2 in | good month |
| August | 17.3 °C / 63 °F | 16.2 °C / 61 °F | 53 mm / 2.1 in | good month |
| September | 16.4 °C / 62 °F | 15.1 °C / 59 °F | 62 mm / 2.4 in | good month |
| October | 14.7 °C / 58 °F | 13.4 °C / 56 °F | 91 mm / 3.6 in | neither best nor good |
| November | 12.6 °C / 55 °F | 11 °C / 52 °F | 106 mm / 4.2 in | neither best nor good |
| December | 11.3 °C / 52 °F | 9.6 °C / 49 °F | 97 mm / 3.8 in | neither best nor good |
Good and best months depend on more than temperature, rain and events. How they are chosen
Each activity on this page has its own good and best months, rated on twenty years of daily weather records. Which measures count, and how much, depends on the activity: humidity for exploring outdoors, wind for the beach, hiking and skiing, snow for skiing alone. Between them, the activities are rated on:
- Daytime highs
- Night-time lows
- How warm it feels
- Humidity
- How much of the day is sunny
- Hours of daylight
- Monthly rainfall
- How many days it rains
- Days of heavy rain
- Wind
- Snowfall and days with snow
- Major events, such as festivals
The chart shows the good and best months for exploring outdoors.
The event icon marks a month that an event lifts to good or best, such as a festival or a natural spectacle. Choose “Weather only” in the toolbar to rate the months on weather alone.
Best months by activity
Exploring outdoors
Mild days and nights, mostly dry and bright. The default for 'when should I go'.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: neither
- MMay: good
- JJune: good
- JJuly: good
- AAugust: good
- SSeptember: good
- OOctober: neither
- NNovember: neither
- DDecember: neither
- Good
- May–September
Why these months
May · good
In its favour: precipitation 49 mm / 1.9 in, share of daylight that is sunny 77%, days with heavy rain 1.1 days, wet days 9.1 days, average daily low 11.5 °C / 53 °F.
Against: feels like (high) 10.2 °C / 50 °F, average daily high 12.7 °C / 55 °F, relative humidity 83%.
June · good
In its favour: precipitation 48 mm / 1.9 in, share of daylight that is sunny 75%, feels like (high) 13.5 °C / 56 °F, days with heavy rain 1.3 days, average daily high 15.1 °C / 59 °F, wet days 8.8 days, average daily low 14 °C / 57 °F.
Against: relative humidity 84%.
July · good
In its favour: feels like (high) 15.9 °C / 61 °F, precipitation 55 mm / 2.2 in, share of daylight that is sunny 75%, average daily high 17 °C / 63 °F, days with heavy rain 1.7 days, wet days 9.2 days, average daily low 15.9 °C / 61 °F.
Against: relative humidity 84%.
August · good
In its favour: feels like (high) 15.8 °C / 60 °F, precipitation 53 mm / 2.1 in, share of daylight that is sunny 75%, average daily high 17.3 °C / 63 °F, days with heavy rain 1.4 days, wet days 9.8 days, average daily low 16.2 °C / 61 °F.
Against: relative humidity 82%.
September · good
In its favour: feels like (high) 14.4 °C / 58 °F, share of daylight that is sunny 73%, precipitation 62 mm / 2.4 in, average daily high 16.4 °C / 62 °F, days with heavy rain 1.9 days, wet days 9.8 days, average daily low 15.1 °C / 59 °F.
Against: relative humidity 82%.
Beach and swimming
Hot, dry and sunny. Penalises the monsoon hard.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: neither
- MMay: neither
- JJune: neither
- JJuly: neither
- AAugust: neither
- SSeptember: neither
- OOctober: neither
- NNovember: neither
- DDecember: neither
No month is good for this in Isles of Scilly.
Hiking and trekking
Cool enough to climb in, dry enough to enjoy, long enough days.
- JJanuary: neither
- FFebruary: neither
- MMarch: good
- AApril: best
- MMay: best
- JJune: best
- JJuly: best
- AAugust: best
- SSeptember: best
- OOctober: good
- NNovember: neither
- DDecember: neither
- Best
- April–September
- Good
- March, October
Why these months
March · good
In its favour: precipitation 66 mm / 2.6 in, average daily high 9.9 °C / 50 °F, days with heavy rain 1.1 days, average daily low 8.3 °C / 47 °F, share of daylight that is sunny 68%, daylight per day 11.9 h.
Against: wet days 13.4 days, wind (daily max) 40 km/h / 25 mph, feels like (high) 5.3 °C / 42 °F.
April · best
In its favour: average daily high 10.8 °C / 51 °F, precipitation 48 mm / 1.9 in, days with heavy rain 0.9 days, wet days 9.5 days, average daily low 9.5 °C / 49 °F, share of daylight that is sunny 79%, daylight per day 13.8 h, feels like (high) 7.4 °C / 45 °F.
Against: wind (daily max) 34 km/h / 21 mph.
May · best
In its favour: average daily high 12.7 °C / 55 °F, precipitation 49 mm / 1.9 in, days with heavy rain 1.1 days, wet days 9.1 days, average daily low 11.5 °C / 53 °F, share of daylight that is sunny 77%, daylight per day 15.4 h, feels like (high) 10.2 °C / 50 °F, wind (daily max) 33 km/h / 20 mph.
June · best
In its favour: average daily high 15.1 °C / 59 °F, precipitation 48 mm / 1.9 in, days with heavy rain 1.3 days, wet days 8.8 days, feels like (high) 13.5 °C / 56 °F, average daily low 14 °C / 57 °F, share of daylight that is sunny 75%, daylight per day 16.3 h, wind (daily max) 31 km/h / 19 mph.
July · best
In its favour: average daily high 17 °C / 63 °F, precipitation 55 mm / 2.2 in, days with heavy rain 1.7 days, wet days 9.2 days, feels like (high) 15.9 °C / 61 °F, share of daylight that is sunny 75%, daylight per day 15.9 h, average daily low 15.9 °C / 61 °F, wind (daily max) 32 km/h / 20 mph.
August · best
In its favour: average daily high 17.3 °C / 63 °F, precipitation 53 mm / 2.1 in, days with heavy rain 1.4 days, feels like (high) 15.8 °C / 60 °F, wet days 9.8 days, share of daylight that is sunny 75%, daylight per day 14.4 h, average daily low 16.2 °C / 61 °F, wind (daily max) 33 km/h / 20 mph.
September · best
In its favour: average daily high 16.4 °C / 62 °F, precipitation 62 mm / 2.4 in, days with heavy rain 1.9 days, feels like (high) 14.4 °C / 58 °F, wet days 9.8 days, share of daylight that is sunny 73%, daylight per day 12.6 h, average daily low 15.1 °C / 59 °F.
Against: wind (daily max) 34 km/h / 21 mph.
October · good
In its favour: average daily high 14.7 °C / 58 °F, precipitation 91 mm / 3.6 in, feels like (high) 11.7 °C / 53 °F, average daily low 13.4 °C / 56 °F, share of daylight that is sunny 65%, days with heavy rain 2.7 days, daylight per day 10.7 h.
Against: wet days 13.7 days, wind (daily max) 39 km/h / 24 mph.
An activity is listed only where it applies: skiing at ski destinations, beach and swimming at beach destinations. The nearest ski area is Glencoe Mountain Resort, 750 km away.
Weather averages
Monthly averages over twenty years, 2006–2025. Highs, lows and precipitation are in the chart at the top.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels like (high) | 5.2 °C | 4.7 °C | 5.3 °C | 7.4 °C | 10.2 °C | 13.5 °C | 15.9 °C | 15.8 °C | 14.4 °C | 11.7 °C | 8.2 °C | 6 °C |
| Days with heavy rain | 2.5 days | 1.8 days | 1.1 days | 0.9 days | 1.1 days | 1.3 days | 1.7 days | 1.4 days | 1.9 days | 2.7 days | 3 days | 2.6 days |
| Time rain usually falls | 1 am | 9 am | 6 pm | 4 am | 4 am | 6 am | 8 am | 8 am | 5 am | 4 am | 2 am | 10 am |
| Sunshine per day | 4.6 h | 6.2 h | 8.1 h | 10.9 h | 11.9 h | 12.1 h | 11.8 h | 10.9 h | 9.3 h | 7 h | 5.4 h | 4.1 h |
| Relative humidity | 77% | 78% | 79% | 81% | 83% | 84% | 84% | 82% | 82% | 81% | 79% | 78% |
Sea temperature
Averaged over a shorter period (2022–2025) than the twenty-year averages above.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature 2022–2025 | 10.9 °C | 10.7 °C | 10.6 °C | 11.2 °C | 13.4 °C | 15.1 °C | 16.4 °C | 17 °C | 16 °C | 14.4 °C | 13.2 °C | 11.9 °C |
| Sea temperature (daily max) 2022–2025 | 11 °C | 10.7 °C | 10.7 °C | 11.4 °C | 13.7 °C | 15.4 °C | 16.7 °C | 17.2 °C | 16.2 °C | 14.5 °C | 13.2 °C | 12 °C |
- Very cold 10 °C or less
- Cold 10 to 15 °C
- Cool 15 to 20 °C
- Comfortable 20 to 25 °C
- Warm 25 to 28 °C
- Very warm over 28 °C
The words describe how the water feels to swim in. They are ours, not an official standard.
Air quality
Averaged over a shorter period (2022–2025) than the twenty-year averages above, and not counted towards good or best months.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Air pollution (PM2.5) 2022–2025 | 8.8 µg/m³ | 9.3 µg/m³ | 10.5 µg/m³ | 11 µg/m³ | 11 µg/m³ | 11.4 µg/m³ | 10.2 µg/m³ | 11.1 µg/m³ | 10.1 µg/m³ | 10.2 µg/m³ | 9.6 µg/m³ | 8.2 µg/m³ |
| Air pollution (PM2.5, daily peak) 2022–2025 | 11.8 µg/m³ | 12.8 µg/m³ | 14.4 µg/m³ | 14.7 µg/m³ | 14.8 µg/m³ | 15.1 µg/m³ | 13.5 µg/m³ | 15 µg/m³ | 13.4 µg/m³ | 13.6 µg/m³ | 12.7 µg/m³ | 11 µg/m³ |
- Good 15 µg/m³ or less
- Fair 15 to 25 µg/m³
- Moderate 25 to 37.5 µg/m³
- Poor 37.5 to 50 µg/m³
- Very poor 50 to 75 µg/m³
- Extremely poor over 75 µg/m³
Each figure is compared with the World Health Organization's guideline for a day's air, 15 µg/m³ or less, and with its interim targets above that. The words are ours: the WHO does not name its steps. The figures are modelled monthly averages, so single days can be well above them. The daily peak is the average of each day's highest hour, shaded on the same scale.