Saint John climate — normals and trends
Saint John (Canada) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 5.8 °C and it receives 1,299 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 August (16.1 °C on average) and the coldest is January (-5.5 °C). Rainfall peaks in November.
Saint John averages 120 frost days, 0 hot days (≥ 30 °C) and 139 rainy days per year.
Saint John has warmed by +1.4 °C between 1940 and 2025, or +0.17 °C per decade. This trend is statistically significant.
The number of frost days there went from about 128 to 112 per year over the period.
The hottest day of the period reached 25.4 °C (on 26 August 1993) and the coldest -27.4 °C (on 4 February 2023).
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
Saint JohnNew Brunswick
- coords
- 45.27°, -66.06°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
5.8°C
Average daily high
8.4°C
Average daily low
3.3°C
Annual rainfall
1,299mm
Sunshine / day
8.1h
Mean relative humidity
79%
Average peak wind
25.5km/h
Seasonal range
21.6°C
Frost days (< 0 °C)
120 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
139 d/yr
Annual snowfall
155.9 cm
Average feels-like high
5.2 °C
Average feels-like low
-1.0 °C
Average peak gust
43.1 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
13.1 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.4 °C
since 1940
+0.2 °C per decade · r² = 0.28 · 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
25.4 °C
26 August 1993
Coldest day
-27.4 °C
4 February 2023
Wettest day
112 mm
21 August 1950
Windiest day
72.2 km/h
2 February 1976
Strongest gust
134.3 km/h
2 January 1945
Hottest feels-like
27.1 °C
24 August 2015
Coldest feels-like
-37.3 °C
4 February 2023
Snowiest day
30.0 cm
7 March 1999
Sunniest day
15.0 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 | -1.5 °C | +0.4 °C | 65 mm | -47 mm |
| Feb | -1.4 °C | +0.1 °C | 73 mm | -24 mm |
| Mar | 3.9 °C | +2.2 °C | 174 mm | +69 mm |
| Apr | 6.8 °C | +0.9 °C | 144 mm | +41 mm |
| May | 11.2 °C | +0.7 °C | 116 mm | +14 mm |
| Jun | 15.9 °C | +1.2 °C | 73 mm | -32 mm |
| Jul | 19.0 °C | +1.3 °C | 37 mm | -62 mm |
| Aug | 19.4 °C | +1.2 °C | 22 mm | -74 mm |
| Sep | 17.7 °C | +1.9 °C | 44 mm | -61 mm |
| Oct | 13.4 °C | +1.8 °C | 128 mm | +11 mm |
| Nov | 7.0 °C | +0.3 °C | 121 mm | -10 mm |
| Dec | 0.5 °C | -0.6 °C | 127 mm | +1 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 Saint John?
Saint John has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 5.8 °C and it receives 1,299 mm of precipitation per year.
What is the hottest day ever recorded in Saint John?
The hottest day measured in Saint John between 1940 and 2025 was 26 August 1993, reaching 25.4 °C.
What is the coldest day in Saint John?
The coldest day measured in Saint John between 1940 and 2025 was 4 February 2023, at -27.4 °C.
Does it snow in Saint John?
Yes. Saint John gets on average 155.9 cm of snow per year and has around 120 frost days.
Has the climate of Saint John warmed?
Yes: Saint John warmed by +1.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Saint John?
The wettest day measured in Saint John between 1940 and 2025 was 21 August 1950, with 112 mm of rain in 24 hours.
What was the windiest day in Saint John?
The windiest day measured in Saint John between 1940 and 2025 was 2 February 1976, with winds reaching 72.2 km/h.
What is the warmest month in Saint John?
The warmest month in Saint John is August (16.1 °C on average); the coldest is January (-5.5 °C).
How much does it rain in Saint John?
Saint John receives on average 1,299 mm of precipitation per year, spread over about 139 rainy days.
Is it sunny in Saint John?
Saint John gets on average 8.1 hours of sunshine per day, roughly 2,957 hours per year over 1940-2025.
What is the biggest single-day snowfall in Saint John?
The heaviest 24-hour snowfall measured in Saint John between 1940 and 2025 was 7 March 1999, with 30.0 cm.
Are there tropical nights in Saint John?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Saint John.
What was the most extreme apparent temperature in Saint John?
In Saint John, between 1940 and 2025, the highest apparent temperature reached 27.1 °C on 24 August 2015, and the lowest was -37.3 °C on 4 February 2023.
Compare Saint John with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Saint John