April is one of the cooler months of the year in St. Catharines, with average highs near 10.4°C and lows around 2°C (mean 6.2°C). It is about average for rainfall, averaging 67 mm of rainfall and 78% relative humidity across the period.
April is one of the cooler months of the year in St. Catharines. Across 45 years of records, the warmest April in St. Catharines was 2010 — when the month averaged 9°C — while the coldest was 2018 at 3.4°C. Typical April days reach 10.4°C with nights near 2°C. The long-term trend is warming, about 0.2°C per decade.
April is about average for rainfall in St. Catharines, averaging 67 mm of rainfall. The wettest April on record was 2017 with 120 mm, while the driest was 1997 at 27 mm.
Relative humidity in St. Catharines during April averages 78%. The most humid April was 1984 at 84%, and the least humid was 2021 at 73%.
April receives about 4.5 kWh/m²/day of solar energy in St. Catharines. The sunniest April was 2010 at 5.3 kWh/m²/day, and the cloudiest were 1996 and 2019 at 3.7.
Average wind speed in St. Catharines during April is 3.5 m/s. The windiest April was 1982 at 4.5 m/s, while the calmest was 1992 at 2.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 6.1°C | 5.9°C | 6.3°C | 6.1°C | 7.2°C | +1.1°C |
| Avg High | 10.3°C | 10.2°C | 10.4°C | 10.4°C | 11.4°C | +1.1°C |
| Avg Low | 1.9°C | 1.6°C | 2.2°C | 1.9°C | 3.0°C | +1.1°C |
| Avg Rain | 59 mm | 54 mm | 76 mm | 81 mm | 62 mm | +3 mm |
April temperatures in St. Catharines have risen by about 1.6°C between 1981–1985 and 2021–2025.
April has ranged from a record low of -10°C (1982) to a record high of 24°C (2023).
Rainfall in April is about average for rainfall, averaging 67 mm, with a wettest year of 120 mm.
A good time to visit St. Catharines
April is a good time to visit St. Catharines, with days averaging 10.4°C and nights around 2°C (mean 6.2°C, cooler than St. Catharines's yearly average) and moderate rainfall. July and August are marginally more temperate, but April still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 11.5°C | 7.1°C | 2.6°C | 22.9°C | -3.6°C | 56 mm | 73% | 3.6 m/s | 4.6 |
| 2024 | 12.4°C | 8.4°C | 4.4°C | 19.6°C | -0.5°C | 92 mm | 78% | 3.5 m/s | 4.1 |
| 2023 | 12.4°C | 8.0°C | 3.7°C | 24.0°C | -3.9°C | 80 mm | 77% | 3.3 m/s | 4.6 |
| 2022 | 10.4°C | 6.1°C | 1.9°C | 22.2°C | -3.1°C | 54 mm | 77% | 3.4 m/s | 4.6 |
| 2021 | 12.1°C | 7.8°C | 3.5°C | 21.9°C | -3.4°C | 42 mm | 73% | 3.3 m/s | 4.5 |
| 2020 | 9.3°C | 5.5°C | 1.8°C | 14.8°C | -1.8°C | 46 mm | 76% | 3.8 m/s | 4.6 |
| 2019 | 9.5°C | 5.7°C | 1.9°C | 16.5°C | -6.6°C | 79 mm | 84% | 3.5 m/s | 3.7 |
| 2018 ❄️ | 6.9°C | 3.4°C | -0.1°C | 17.4°C | -3.7°C | 94 mm | 78% | 3.9 m/s | 4.2 |
| 2017 🌧️ | 12.8°C | 8.5°C | 4.3°C | 23.1°C | -2.1°C | 120 mm | 83% | 3.5 m/s | 4.3 |
| 2016 | 8.4°C | 4.6°C | 0.7°C | 18.4°C | -6.3°C | 50 mm | 76% | 3.5 m/s | 4.8 |
| 2015 | 11.0°C | 6.1°C | 1.3°C | 17.6°C | -3.1°C | 70 mm | 77% | 3.2 m/s | 4.8 |
| 2014 | 10.3°C | 5.3°C | 0.2°C | 17.9°C | -6.9°C | 91 mm | 79% | 3.3 m/s | 4.6 |
| 2013 | 10.2°C | 5.9°C | 1.7°C | 20.0°C | -3.3°C | 85 mm | 79% | 4.1 m/s | 4.4 |
| 2012 | 11.1°C | 6.8°C | 2.6°C | 20.6°C | -0.5°C | 53 mm | 74% | 3.7 m/s | 4.7 |
| 2011 | 9.9°C | 6.1°C | 2.4°C | 19.8°C | -1.3°C | 115 mm | 84% | 3.8 m/s | 3.8 |
| 2010 🔥 | 13.7°C | 9.0°C | 4.3°C | 21.4°C | -0.7°C | 53 mm | 74% | 3.2 m/s | 5.3 |
| 2009 | 10.8°C | 6.8°C | 2.7°C | 20.5°C | -2.4°C | 93 mm | 79% | 4 m/s | 4.7 |
| 2008 | 12.9°C | 8.1°C | 3.3°C | 22.1°C | -2.6°C | 53 mm | 79% | 2.9 m/s | 5.2 |
| 2007 | 8.6°C | 5.2°C | 1.8°C | 18.6°C | -4.6°C | 59 mm | 81% | 3.9 m/s | 3.9 |
| 2006 | 11.7°C | 7.4°C | 3.2°C | 19.5°C | -1.9°C | 57 mm | 78% | 3.2 m/s | 5 |
| 2005 | 10.3°C | 6.3°C | 2.3°C | 17.6°C | -0.8°C | 101 mm | 81% | 3.4 m/s | 4.5 |
| 2004 | 10.0°C | 6.3°C | 2.5°C | 18.2°C | -4.6°C | 83 mm | 82% | 3.5 m/s | 4.4 |
| 2003 | 8.7°C | 4.3°C | -0.1°C | 17.5°C | -9.9°C | 52 mm | 81% | 3.7 m/s | 4.5 |
| 2002 | 9.7°C | 5.9°C | 2.1°C | 21.0°C | -3.0°C | 103 mm | 83% | 3.2 m/s | 4 |
| 2001 | 11.2°C | 6.5°C | 1.8°C | 18.9°C | -3.0°C | 48 mm | 79% | 2.9 m/s | 4.7 |
| 2000 | 9.6°C | 6.0°C | 2.4°C | 17.3°C | -3.2°C | 111 mm | 79% | 3.2 m/s | 3.9 |
| 1999 | 10.8°C | 6.5°C | 2.3°C | 17.4°C | -1.9°C | 68 mm | 76% | 3.5 m/s | 4.9 |
| 1998 | 11.9°C | 7.6°C | 3.4°C | 18.0°C | -2.2°C | 55 mm | 73% | 3 m/s | 5.1 |
| 1997 | 9.5°C | 5.1°C | 0.8°C | 17.4°C | -5.7°C | 27 mm | 74% | 3.3 m/s | 4.7 |
| 1996 | 8.1°C | 4.0°C | -0.1°C | 16.6°C | -4.4°C | 72 mm | 78% | 3.8 m/s | 3.7 |
| 1995 | 8.2°C | 3.9°C | -0.5°C | 16.2°C | -6.1°C | 32 mm | 75% | 3.6 m/s | 4.2 |
| 1994 | 10.8°C | 5.9°C | 1.0°C | 19.9°C | -4.8°C | 54 mm | 76% | 4 m/s | 4.8 |
| 1993 | 10.4°C | 6.1°C | 1.8°C | 17.9°C | -2.7°C | 35 mm | 78% | 3.2 m/s | 4 |
| 1992 | 9.4°C | 5.2°C | 1.1°C | 17.9°C | -5.0°C | 62 mm | 78% | 2.8 m/s | 4.1 |
| 1991 | 11.6°C | 7.6°C | 3.6°C | 18.9°C | -3.1°C | 78 mm | 82% | 3.7 m/s | 3.9 |
| 1990 | 10.9°C | 6.7°C | 2.5°C | 22.8°C | -4.0°C | 58 mm | 79% | 3.4 m/s | 4.5 |
| 1989 | 8.6°C | 4.3°C | 0.0°C | 15.2°C | -4.3°C | 42 mm | 75% | 3 m/s | 4.4 |
| 1988 | 10.1°C | 5.7°C | 1.2°C | 16.0°C | -3.3°C | 52 mm | 78% | 3.3 m/s | 4.1 |
| 1987 | 12.3°C | 8.1°C | 3.9°C | 23.0°C | -4.0°C | 43 mm | 80% | 3.5 m/s | 4.6 |
| 1986 | 11.3°C | 7.0°C | 2.7°C | 23.0°C | -2.7°C | 67 mm | 80% | 3 m/s | 4.8 |
| 1985 | 11.5°C | 7.5°C | 3.4°C | 23.8°C | -3.7°C | 66 mm | 82% | 3.6 m/s | 5.2 |
| 1984 | 9.9°C | 6.2°C | 2.5°C | 18.6°C | -2.3°C | 75 mm | 84% | 3 m/s | 4.6 |
| 1983 | 9.3°C | 5.6°C | 2.0°C | 16.0°C | -1.7°C | 67 mm | 82% | 3.7 m/s | — |
| 1982 | 8.3°C | 3.8°C | -0.7°C | 17.6°C | -10.0°C | 49 mm | 78% | 4.5 m/s | — |
| 1981 | 11.2°C | 6.5°C | 1.7°C | 17.8°C | -3.6°C | 70 mm | 74% | 4.2 m/s | — |
Actual recorded April data for each year, 1981–2025 — sourced from NASA POWER.
The average high in April is around 10.4°C with lows near 2°C (mean 6.2°C), based on 45 years of NASA POWER data.
April averages 67 mm of rainfall in St. Catharines, about average for rainfall. The wettest on record was 120 mm in 2017.
The hottest April reached 24°C in 2023. The coldest dipped to -10°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average April temperatures have risen by about 1.6°C. Daytime highs moved from 10°C to 11.8°C and overnight lows from 1.8°C to 3.2°C over the same span.
April is one of the cooler months of the year in St. Catharines and about average for rainfall, so plan for around 10.4°C daytime highs and 2°C at night.
Not quite — April is the 6th coolest month in St. Catharines, averaging 6.2°C.
For April in St. Catharines, pack warm layers and a jacket for chilly mornings, with typical highs of 10.4°C and lows of 2°C. Bring an umbrella or light rain jacket too.
Relative humidity in April averages 78% — quite humid.
Average wind speed in April is 3.5 m/s. The windiest April on record averaged 4.5 m/s (1982).
The wettest April on record was 2017 with 120 mm. On average, April sees 67 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in St. Catharines behaves each April, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for April specifically, along with year-by-year records and how the month has changed over the decades.
