Old Harlow climate — normals and trends
Old Harlow (United Kingdom) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 10.1 °C and it receives 593 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 (17.1 °C on average) and the coldest is January (4.0 °C). Rainfall peaks in August.
Old Harlow averages 35 frost days, 1 hot days (≥ 30 °C) and 123 rainy days per year.
Old Harlow has warmed by +1.8 °C between 1940 and 2025, or +0.21 °C per decade. This trend is statistically significant.
The number of frost days there went from about 51 to 19 per year over the period.
The hottest day of the period reached 37.2 °C (on 19 July 2022) and the coldest -13.5 °C (on 25 February 1947).
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
Old HarlowEngland
- coords
- 51.78°, 0.13°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
10.1°C
Average daily high
13.4°C
Average daily low
6.9°C
Annual rainfall
593mm
Sunshine / day
7.7h
Mean relative humidity
80%
Average peak wind
21.6km/h
Seasonal range
13.1°C
Frost days (< 0 °C)
35 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
123 d/yr
Annual snowfall
12.9 cm
Average feels-like high
10.6 °C
Average feels-like low
3.9 °C
Average peak gust
40.9 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
10.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.8 °C
since 1940
+0.2 °C per decade · r² = 0.47 · 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
37.2 °C
19 July 2022
Coldest day
-13.5 °C
25 February 1947
Wettest day
45 mm
20 June 1973
Windiest day
68.1 km/h
16 October 1987
Strongest gust
126.0 km/h
30 October 2000
Hottest feels-like
37.3 °C
25 July 2019
Coldest feels-like
-18.2 °C
25 February 1947
Snowiest day
14.1 cm
4 March 1970
Sunniest day
16.0 h
30 May 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 | 6.2 °C | 0.0 °C | 64 mm | +17 mm |
| Feb | 7.3 °C | +0.4 °C | 48 mm | +8 mm |
| Mar | 12.3 °C | +2.9 °C | 14 mm | -29 mm |
| Apr | 15.6 °C | +3.3 °C | 29 mm | -18 mm |
| May | 18.3 °C | +2.7 °C | 22 mm | -32 mm |
| Jun | 23.2 °C | +4.3 °C | 29 mm | -24 mm |
| Jul | 23.5 °C | +2.5 °C | 62 mm | +10 mm |
| Aug | 22.9 °C | +2.1 °C | 30 mm | -25 mm |
| Sep | 18.8 °C | +0.6 °C | 38 mm | -10 mm |
| Oct | 14.6 °C | +0.4 °C | 52 mm | -0 mm |
| Nov | 11.1 °C | +1.5 °C | 90 mm | +37 mm |
| Dec | 9.4 °C | +2.2 °C | 37 mm | -12 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 Old Harlow?
Old Harlow has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 10.1 °C and it receives 593 mm of precipitation per year.
What is the hottest day ever recorded in Old Harlow?
The hottest day measured in Old Harlow between 1940 and 2025 was 19 July 2022, reaching 37.2 °C.
What is the coldest day in Old Harlow?
The coldest day measured in Old Harlow between 1940 and 2025 was 25 February 1947, at -13.5 °C.
Does it snow in Old Harlow?
Yes. Old Harlow gets on average 12.9 cm of snow per year and has around 35 frost days.
Has the climate of Old Harlow warmed?
Yes: Old Harlow warmed by +1.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Old Harlow?
The wettest day measured in Old Harlow between 1940 and 2025 was 20 June 1973, with 45 mm of rain in 24 hours.
What was the windiest day in Old Harlow?
The windiest day measured in Old Harlow between 1940 and 2025 was 16 October 1987, with winds reaching 68.1 km/h.
What is the warmest month in Old Harlow?
The warmest month in Old Harlow is July (17.1 °C on average); the coldest is January (4.0 °C).
How much does it rain in Old Harlow?
Old Harlow receives on average 593 mm of precipitation per year, spread over about 123 rainy days.
Is it sunny in Old Harlow?
Old Harlow gets on average 7.7 hours of sunshine per day, roughly 2,811 hours per year over 1940-2025.
What is the biggest single-day snowfall in Old Harlow?
The heaviest 24-hour snowfall measured in Old Harlow between 1940 and 2025 was 4 March 1970, with 14.1 cm.
Are there tropical nights in Old Harlow?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Old Harlow.
What was the most extreme apparent temperature in Old Harlow?
In Old Harlow, between 1940 and 2025, the highest apparent temperature reached 37.3 °C on 25 July 2019, and the lowest was -18.2 °C on 25 February 1947.
Compare Old Harlow with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Old Harlow