Grantham climate — normals and trends
Grantham (United Kingdom) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 9.8 °C and it receives 631 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (16.7 °C on average) and the coldest is January (3.8 °C). Rainfall peaks in August.
Grantham averages 40 frost days, 1 hot days (≥ 30 °C) and 129 rainy days per year.
Grantham has warmed by +1.7 °C between 1940 and 2025, or +0.20 °C per decade. This trend is statistically significant.
The number of frost days there went from about 58 to 22 per year over the period.
The hottest day of the period reached 40.3 °C (on 19 July 2022) and the coldest -17.7 °C (on 23 January 1963).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
GranthamEngland
- coords
- 52.91°, -0.64°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
9.8°C
Average daily high
13.2°C
Average daily low
6.4°C
Annual rainfall
631mm
Sunshine / day
7.3h
Mean relative humidity
80%
Average peak wind
22.6km/h
Seasonal range
12.9°C
Frost days (< 0 °C)
40 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
129 d/yr
Annual snowfall
17.8 cm
Average feels-like high
10.1 °C
Average feels-like low
3.2 °C
Average peak gust
41.6 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
10.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.7 °C
since 1940
+0.2 °C per decade · r² = 0.45 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
40.3 °C
19 July 2022
Coldest day
-17.7 °C
23 January 1963
Wettest day
47 mm
20 October 2023
Windiest day
64.5 km/h
3 January 1976
Strongest gust
127.1 km/h
9 February 2020
Hottest feels-like
36.8 °C
25 July 2019
Coldest feels-like
-22.8 °C
25 February 1947
Snowiest day
19.0 cm
26 April 1981
Sunniest day
16.0 h
3 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 5.9 °C | -0.2 °C | 84 mm | +34 mm |
| Feb | 7.7 °C | +0.8 °C | 39 mm | -2 mm |
| Mar | 12.7 °C | +3.3 °C | 25 mm | -22 mm |
| Apr | 16.0 °C | +3.8 °C | 13 mm | -37 mm |
| May | 18.6 °C | +3.1 °C | 27 mm | -31 mm |
| Jun | 23.1 °C | +4.5 °C | 36 mm | -22 mm |
| Jul | 23.2 °C | +2.4 °C | 67 mm | +9 mm |
| Aug | 22.9 °C | +2.4 °C | 18 mm | -43 mm |
| Sep | 18.5 °C | +0.6 °C | 78 mm | +27 mm |
| Oct | 14.1 °C | +0.1 °C | 59 mm | +6 mm |
| Nov | 10.9 °C | +1.5 °C | 119 mm | +65 mm |
| Dec | 9.3 °C | +2.3 °C | 81 mm | +31 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Grantham?
Grantham has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 9.8 °C and it receives 631 mm of precipitation per year.
What is the hottest day ever recorded in Grantham?
The hottest day measured in Grantham between 1940 and 2025 was 19 July 2022, reaching 40.3 °C.
What is the coldest day in Grantham?
The coldest day measured in Grantham between 1940 and 2025 was 23 January 1963, at -17.7 °C.
Does it snow in Grantham?
Yes. Grantham gets on average 17.8 cm of snow per year and has around 40 frost days.
Has the climate of Grantham warmed?
Yes: Grantham warmed by +1.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Grantham?
The wettest day measured in Grantham between 1940 and 2025 was 20 October 2023, with 47 mm of rain in 24 hours.
What was the windiest day in Grantham?
The windiest day measured in Grantham between 1940 and 2025 was 3 January 1976, with winds reaching 64.5 km/h.
What is the warmest month in Grantham?
The warmest month in Grantham is July (16.7 °C on average); the coldest is January (3.8 °C).
How much does it rain in Grantham?
Grantham receives on average 631 mm of precipitation per year, spread over about 129 rainy days.
Is it sunny in Grantham?
Grantham gets on average 7.3 hours of sunshine per day, roughly 2,665 hours per year over 1940-2025.
What is the biggest single-day snowfall in Grantham?
The heaviest 24-hour snowfall measured in Grantham between 1940 and 2025 was 26 April 1981, with 19.0 cm.
Are there tropical nights in Grantham?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Grantham.
What was the most extreme apparent temperature in Grantham?
In Grantham, between 1940 and 2025, the highest apparent temperature reached 36.8 °C on 25 July 2019, and the lowest was -22.8 °C on 25 February 1947.
Compare Grantham with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Grantham