Blenheim climate — normals and trends
Blenheim (New Zealand) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 11.7 °C and it receives 844 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 January (16.3 °C on average) and the coldest is July (6.9 °C). Rainfall peaks in October.
Blenheim averages 1 frost days, 0 hot days (≥ 30 °C) and 114 rainy days per year.
Blenheim 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 2 to 0 per year over the period.
The hottest day of the period reached 33.6 °C (on 7 February 1973) and the coldest -2.1 °C (on 16 August 2011).
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
BlenheimMarlborough
- coords
- -41.52°, 173.95°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
11.7°C
Average daily high
15.3°C
Average daily low
8.4°C
Annual rainfall
844mm
Sunshine / day
10.0h
Mean relative humidity
78%
Average peak wind
20.9km/h
Seasonal range
9.4°C
Frost days (< 0 °C)
1 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
114 d/yr
Annual snowfall
1.1 cm
Average feels-like high
13.3 °C
Average feels-like low
5.7 °C
Average peak gust
44.6 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
15.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.7 °C
since 1940
+0.2 °C per decade · r² = 0.63 · 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
33.6 °C
7 February 1973
Coldest day
-2.1 °C
16 August 2011
Wettest day
96 mm
30 March 1979
Windiest day
55.3 km/h
23 October 2025
Strongest gust
132.8 km/h
25 December 1987
Hottest feels-like
33.1 °C
7 February 1973
Coldest feels-like
-6.5 °C
28 June 1965
Snowiest day
12.2 cm
16 July 1976
Sunniest day
14.9 h
28 December 2025
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 | 18.3 °C | -1.7 °C | 51 mm | -6 mm |
| Feb | 20.3 °C | +0.2 °C | 20 mm | -37 mm |
| Mar | 19.8 °C | +1.2 °C | 37 mm | -24 mm |
| Apr | 16.8 °C | +0.8 °C | 139 mm | +74 mm |
| May | 15.0 °C | +1.6 °C | 95 mm | +24 mm |
| Jun | 12.1 °C | +1.1 °C | 140 mm | +65 mm |
| Jul | 11.7 °C | +1.3 °C | 153 mm | +71 mm |
| Aug | 11.8 °C | +0.6 °C | 25 mm | -56 mm |
| Sep | 14.4 °C | +1.4 °C | 33 mm | -34 mm |
| Oct | 16.4 °C | +1.5 °C | 96 mm | +13 mm |
| Nov | 18.8 °C | +2.1 °C | 50 mm | -19 mm |
| Dec | 19.5 °C | +1.1 °C | 95 mm | +21 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 Blenheim?
Blenheim has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 11.7 °C and it receives 844 mm of precipitation per year.
What is the hottest day ever recorded in Blenheim?
The hottest day measured in Blenheim between 1940 and 2025 was 7 February 1973, reaching 33.6 °C.
What is the coldest day in Blenheim?
The coldest day measured in Blenheim between 1940 and 2025 was 16 August 2011, at -2.1 °C.
Does it snow in Blenheim?
Yes. Blenheim gets on average 1.1 cm of snow per year and has around 1 frost days.
Has the climate of Blenheim warmed?
Yes: Blenheim warmed by +1.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Blenheim?
The wettest day measured in Blenheim between 1940 and 2025 was 30 March 1979, with 96 mm of rain in 24 hours.
What was the windiest day in Blenheim?
The windiest day measured in Blenheim between 1940 and 2025 was 23 October 2025, with winds reaching 55.3 km/h.
What is the warmest month in Blenheim?
The warmest month in Blenheim is January (16.3 °C on average); the coldest is July (6.9 °C).
How much does it rain in Blenheim?
Blenheim receives on average 844 mm of precipitation per year, spread over about 114 rainy days.
Is it sunny in Blenheim?
Blenheim gets on average 10.0 hours of sunshine per day, roughly 3,650 hours per year over 1940-2025.
What is the biggest single-day snowfall in Blenheim?
The heaviest 24-hour snowfall measured in Blenheim between 1940 and 2025 was 16 July 1976, with 12.2 cm.
Are there tropical nights in Blenheim?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Blenheim.
What was the most extreme apparent temperature in Blenheim?
In Blenheim, between 1940 and 2025, the highest apparent temperature reached 33.1 °C on 7 February 1973, and the lowest was -6.5 °C on 28 June 1965.
Compare Blenheim with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Blenheim