Slough climate
Slough (England, United Kingdom) has a temperate oceanic climate (Köppen Cfb). The average temperature over the year is 11 °C51 °F, and about 736 mm29 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Slough climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 745 | 235 | 440 | 682.7 | 11 |
| Feb | 846 | 134 | 440 | 562.2 | 11 |
| Mar | 1050 | 236 | 643 | 522.1 | 7 |
| Apr | 1457 | 440 | 949 | 451.8 | 2 |
| May | 1763 | 846 | 1254 | 572.2 | 0 |
| Jun | 2170 | 1151 | 1661 | 582.3 | 0 |
| Jul | 2374 | 1355 | 1865 | 602.4 | 0 |
| Aug | 2373 | 1355 | 1864 | 672.6 | 0 |
| Sep | 2068 | 1050 | 1559 | 461.8 | 0 |
| Oct | 1560 | 846 | 1253 | 773.0 | 0 |
| Nov | 1151 | 540 | 846 | 773.0 | 3 |
| Dec | 846 | 337 | 541 | 742.9 | 8 |
| Year | 2374 | 134 | 1151 | 73629 | 43 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 94% | 75% | 0.8 | 8:19 |
| Feb | 92% | 75% | 1.5 | 9:53 |
| Mar | 87% | 73% | 2.6 | 11:42 |
| Apr | 83% | 68% | 4.0 | 13:47 |
| May | 80% | 71% | 4.9 | 15:35 |
| Jun | 77% | 72% | 5.3 | 16:36 |
| Jul | 74% | 69% | 5.1 | 16:11 |
| Aug | 76% | 72% | 4.2 | 14:35 |
| Sep | 80% | 68% | 3.2 | 12:33 |
| Oct | 87% | 73% | 1.9 | 10:33 |
| Nov | 93% | 75% | 1.0 | 8:45 |
| Dec | 95% | 76% | 0.7 | 7:51 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Slough is like
The warmest month is July, with an average high of 23 °C74 °F and a low of 13 °C55 °F. The coldest is January, when highs average 7 °C45 °F and lows 2 °C35 °F. There is a clear seasonal cycle, with 13.7 °C24.7 °F between the average temperature of the warmest and the coolest month.
Annual precipitation is moderate at about 736 mm29 in. Rain is spread fairly evenly through the year. The wettest month is November (77 mm3.0 in), the driest is April (45 mm1.8 in).
Relative humidity ranges from 74% in July to 95% in December. The clearest skies (lowest average cloud amount, 68%) are typical of September. Average wind speed near the ground ranges from 11 km/h (7 mph) in June to 14 km/h (9 mph) in January. Daylight lasts from about 7.9 hours in December to 16.6 hours in June.
Best time to visit Slough
Based on these averages, the most comfortable months for sightseeing and outdoor activities are June–September: average highs of 20 °C68 °F to 23 °C74 °F with 46 mm1.8 in to 67 mm2.6 in of precipitation per month.
The most challenging month is January, which is cold, with average highs of 7 °C45 °F.
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Slough
- Winter (December–February) — highs 745 to 8 °C46 °F, lows 134 to 3 °C37 °F, about 66 mm2.6 in of precipitation a month. Pack a warm coat, layers and closed shoes.
- Spring (March–May) — highs 1050 to 17 °C63 °F, lows 236 to 8 °C46 °F, about 51 mm2.0 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
- Summer (June–August) — highs 2170 to 23 °C74 °F, lows 1151 to 13 °C55 °F, about 62 mm2.4 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
- Autumn (September–November) — highs 1151 to 20 °C68 °F, lows 540 to 10 °C50 °F, about 67 mm2.6 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
How Slough compares
Compared with Reading, about 27 km to the west, Slough has practically the same average temperature and receives a similar amount of precipitation.
Of the 66 places in the United Kingdom covered by World Climates, Slough is the 22nd warmest by annual mean temperature and the 53rd wettest by annual precipitation. See all of them on the United Kingdom climate page.
Places in other countries with the most similar temperature and rainfall pattern: Brugge (Belgium, Cfb), Rouen (France, Cfb) and Amiens (France, Cfb).
The same NASA POWER grid cell also contains Harrow (pop. 149,246), High Wycombe (pop. 133,204), Watford (pop. 125,707) and Woking (pop. 103,900). Their long-term averages in this dataset are essentially the same as for Slough, so they do not have separate pages.
Nearby places
- Reading 27 km · 10 °C51 °F · 752 mm30 in
- London 33 km · 11 °C51 °F · 709 mm28 in
- Luton 43 km · 10 °C50 °F · 712 mm28 in
- Basingstoke 44 km · 10 °C50 °F · 752 mm30 in
- Bexley 52 km · 11 °C51 °F · 709 mm28 in
- Crawley 53 km · 11 °C51 °F · 765 mm30 in
- Oxford 53 km · 10 °C50 °F · 734 mm29 in
- Milton Keynes 60 km · 10 °C50 °F · 712 mm28 in
Frequently asked questions
What is the warmest month in Slough?
July is the warmest month in Slough, with an average high of 23 °C (74 °F) and an average low of 13 °C (55 °F).
What is the coldest month in Slough?
January is the coldest month, with an average high of 7 °C (45 °F) and an average low of 2 °C (35 °F).
When does it rain the most in Slough?
November is the wettest month with about 77 mm (3.0 in) of precipitation; April is the driest with about 45 mm (1.8 in).
What is the best time to visit Slough?
Judging by long-term averages, the most comfortable months are June–September.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 87 m, while Slough lies at about 33 m. Temperatures on this page were therefore adjusted by +0.4 °C0.6 °F using the standard lapse rate of 6.5 °C per 1,000 m.