Climate averages 1991–2020
Delta weather
in May.
A mild, moderately 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 mild month in Delta: daytime highs average 16.8°C and nights cool to about 8.8°C. By daytime temperature it is the 5th warmest of the 12 months.
Expect about 69 mm of rain on roughly 10 days, which makes May a moderately wet month (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 15 h 16 min on an average May day.
The nearest other city in this atlas is New Westminster (17 km away). In May its highs average 16.6°C, about as warm as Delta, with 117 mm of rain.
Among the 86 cities listed in Canada, Delta ranks joint 51st of 86 for the warmest May highs and 13th of 86 for the driest May (rainfall, lowest first). The mean May high of those 86 cities is 17.0°C; Delta is 0.2°C cooler than that mean.
From May to June, average highs rise by 2.5°C to 19.2°C, and monthly rainfall falls from 69 mm to 49 mm.
The annual picture
May in context
Monthly rainfall
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
Delta climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 6.1°C1.4°C | 1.4°C | 209 | 18.0 | 8.79 h |
| February | 7.7°C1.6°C | 1.6°C | 125 | 14.3 | 10.110 h |
| March | 9.8°C3.1°C | 3.1°C | 156 | 17.3 | 11.912 h |
| April | 12.8°C5.4°C | 5.4°C | 109 | 13.7 | 13.714 h |
| May, selected | 16.8°C8.8°C | 8.8°C | 69 | 10.1 | 15.315 h |
| June | 19.2°C11.6°C | 11.6°C | 49 | 8.1 | 16.116 h |
| July | 22.8°C14.2°C | 14.2°C | 28 | 4.6 | 15.816 h |
| August | 23.0°C14.4°C | 14.4°C | 41 | 4.8 | 14.414 h |
| September | 19.6°C12.0°C | 12.0°C | 72 | 8.2 | 12.713 h |
| October | 13.6°C7.9°C | 7.9°C | 155 | 14.3 | 10.811 h |
| November | 8.6°C4.0°C | 4.0°C | 232 | 18.4 | 9.29 h |
| December | 5.7°C1.4°C | 1.4°C | 198 | 17.7 | 8.38 h |
Rainfall is the average of the 30 separate monthly totals. A rain 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
- New Westminster in MayCanada · 17 kmHigh 16.6°C · Low 7.1°C · 117 mm rain
- Surrey in MayCanada · 17 kmHigh 16.7°C · Low 7.3°C · 85 mm rain
- Vancouver in MayCanada · 18 kmHigh 15.8°C · Low 8.4°C · 117 mm rain
- Burnaby in MayCanada · 21 kmHigh 16.4°C · Low 8.0°C · 117 mm rain
- North Vancouver in MayCanada · 25 kmHigh 16.1°C · Low 8.4°C · 117 mm rain
- Langley in MayCanada · 29 kmHigh 17.2°C · Low 7.5°C · 85 mm rain
- Coquitlam in MayCanada · 29 kmHigh 17.4°C · Low 7.7°C · 134 mm rain
- Maple Ridge in MayCanada · 36 kmHigh 17.1°C · Low 7.2°C · 154 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 Delta) is explained once on the Delta year overview and on the Sources, method and limits page.