Climate averages 1991–2020
Saint John weather
in May.
A cool, wet month: the 5th warmest and the 4th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
May is a cool month in Saint John: daytime highs average 13.4°C and nights cool to about 6.1°C. By daytime temperature it is the 5th warmest of the 12 months.
Expect about 104 mm of rain on roughly 12 days, which makes May a wet month (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 51 min on an average May day.
The nearest other city in this atlas is Moncton (134 km away). In May its highs average 15.3°C, 1.9°C warmer than Saint John, with 85 mm of rain.
Among the 86 cities listed in Canada, Saint John ranks 82nd of 86 for the warmest May highs and joint 76th of 86 for the driest May (rainfall, lowest first). The mean May high of those 86 cities is 17.0°C; Saint John is 3.6°C cooler than that mean.
From May to June, average highs rise by 4.4°C to 17.8°C, and monthly rainfall rises from 104 mm to 108 mm.
The annual picture
May in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Saint John climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -2.6°C-10.2°C | -10.2°C | 112 | 11.6 | 9.29 h |
| February | -1.7°C-9.1°C | -9.1°C | 96 | 10.3 | 10.410 h |
| March | 1.9°C-4.9°C | -4.9°C | 112 | 11.4 | 11.912 h |
| April | 7.4°C0.7°C | 0.7°C | 105 | 12.3 | 13.513 h |
| May, selected | 13.4°C6.1°C | 6.1°C | 104 | 12.3 | 14.815 h |
| June | 17.8°C11.0°C | 11.0°C | 108 | 12.1 | 15.616 h |
| July | 20.8°C14.6°C | 14.6°C | 91 | 11.0 | 15.315 h |
| August | 21.0°C14.9°C | 14.9°C | 80 | 9.3 | 14.114 h |
| September | 17.8°C11.8°C | 11.8°C | 108 | 10.0 | 12.613 h |
| October | 12.3°C6.6°C | 6.6°C | 133 | 10.9 | 11.011 h |
| November | 6.7°C1.0°C | 1.0°C | 128 | 11.8 | 9.610 h |
| December | 1.2°C-5.3°C | -5.3°C | 137 | 13.1 | 8.89 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
May in nearby cities
- Moncton in MayCanada · 134 kmHigh 15.3°C · Low 5.7°C · 85 mm rain
- Dartmouth in MayCanada · 206 kmHigh 13.6°C · Low 6.0°C · 83 mm rain
- Halifax in MayCanada · 207 kmHigh 12.0°C · Low 5.8°C · 83 mm rain
- Québec in MayCanada · 433 kmHigh 17.1°C · Low 6.7°C · 101 mm rain
- Sherbrooke in MayCanada · 457 kmHigh 17.3°C · Low 7.0°C · 117 mm rain
- Sydney, Canada in MayCanada · 466 kmHigh 11.5°C · Low 4.7°C · 86 mm rain
- Lawrence (Massachusetts), United States in MayUnited States · 498 kmHigh 19.2°C · Low 9.4°C · 78 mm rain
- Manchester, United States in MayUnited States · 499 kmHigh 19.1°C · Low 8.7°C · 80 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Saint John) is explained once on the Saint John year overview and on the Sources, method and limits page.