April is one of the cooler months of the year in Waterloo, with average highs near 11.3°C and lows around -0.1°C (mean 5.6°C). It is about average for rainfall, averaging 62 mm of rainfall and 78% relative humidity across the period.
April is one of the cooler months of the year in Waterloo. Across 45 years of records, the warmest April in Waterloo was 2010 — when the month averaged 9.1°C — while the coldest was 2018 at 1.6°C. Typical April days reach 11.3°C with nights near -0.1°C. The long-term April temperature trend is broadly flat.
April is about average for rainfall in Waterloo, averaging 62 mm of rainfall. The wettest April on record was 2017 with 118 mm, while the driest was 1997 at 21 mm.
Relative humidity in Waterloo during April averages 78%. The most humid April was 1985 at 85%, and the least humid was 2010 at 69%.
April receives about 4.5 kWh/m²/day of solar energy in Waterloo. The sunniest April was 2010 at 5.5 kWh/m²/day, and the cloudiest were 1995 and 2019 at 3.7.
Average wind speed in Waterloo during April is 3.9 m/s. The windiest April was 1981 at 4.8 m/s, while the calmest were 1989 and 1998 at 3.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 5.6°C | 5.6°C | 5.8°C | 5.2°C | 6.1°C | +0.5°C |
| Avg High | 11.3°C | 11.2°C | 11.5°C | 10.9°C | 11.9°C | +0.6°C |
| Avg Low | -0.1°C | -0.1°C | 0.0°C | -0.6°C | 0.4°C | +0.5°C |
| Avg Rain | 52 mm | 51 mm | 66 mm | 77 mm | 58 mm | +6 mm |
April temperatures in Waterloo have risen by about 1.3°C between 1981–1985 and 2021–2025.
April has ranged from a record low of -18.2°C (2003) to a record high of 26.1°C (2023).
Rainfall in April is about average for rainfall, averaging 62 mm, with a wettest year of 118 mm.
A good time to visit Waterloo
April is a good time to visit Waterloo, with days averaging 11.3°C and nights around -0.1°C (mean 5.6°C, cooler than Waterloo'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 | 12.6°C | 6.2°C | -0.1°C | 24.7°C | -6.2°C | 61 mm | 73% | 4.2 m/s | 4.8 |
| 2024 | 13.4°C | 7.7°C | 2.0°C | 22.1°C | -4.0°C | 80 mm | 77% | 4 m/s | 4.3 |
| 2023 | 13.0°C | 7.1°C | 1.1°C | 26.1°C | -6.1°C | 80 mm | 77% | 3.5 m/s | 4.5 |
| 2022 | 10.4°C | 4.8°C | -0.8°C | 24.9°C | -4.9°C | 48 mm | 78% | 3.7 m/s | 4.5 |
| 2021 | 12.1°C | 6.7°C | 1.3°C | 23.3°C | -5.8°C | 46 mm | 74% | 3.5 m/s | 4.5 |
| 2020 | 10.0°C | 4.4°C | -1.1°C | 15.9°C | -4.8°C | 35 mm | 73% | 3.8 m/s | 4.6 |
| 2019 | 9.5°C | 4.6°C | -0.4°C | 18.8°C | -9.1°C | 94 mm | 83% | 4 m/s | 3.7 |
| 2018 ❄️ | 6.3°C | 1.6°C | -3.1°C | 18.4°C | -7.4°C | 98 mm | 78% | 3.9 m/s | 4.2 |
| 2017 🌧️ | 13.6°C | 7.7°C | 1.8°C | 23.8°C | -4.0°C | 118 mm | 81% | 4.2 m/s | 4.5 |
| 2016 | 8.5°C | 2.9°C | -2.7°C | 21.9°C | -12.9°C | 52 mm | 78% | 3.4 m/s | 4.7 |
| 2015 | 11.8°C | 5.7°C | -0.3°C | 20.9°C | -5.2°C | 60 mm | 77% | 4 m/s | 4.7 |
| 2014 | 11.0°C | 4.9°C | -1.2°C | 21.4°C | -8.9°C | 83 mm | 79% | 4.1 m/s | 4.6 |
| 2013 | 9.8°C | 4.3°C | -1.3°C | 22.6°C | -7.4°C | 110 mm | 82% | 4.2 m/s | 4.2 |
| 2012 | 11.7°C | 5.5°C | -0.8°C | 21.6°C | -4.0°C | 35 mm | 73% | 3.9 m/s | 4.9 |
| 2011 | 11.3°C | 5.7°C | 0.0°C | 22.4°C | -4.2°C | 83 mm | 81% | 4.4 m/s | 3.9 |
| 2010 🔥 | 15.9°C | 9.1°C | 2.2°C | 24.7°C | -2.7°C | 41 mm | 69% | 3.7 m/s | 5.5 |
| 2009 | 11.5°C | 6.0°C | 0.5°C | 24.4°C | -4.8°C | 97 mm | 78% | 4.5 m/s | 4.7 |
| 2008 | 14.6°C | 7.8°C | 1.0°C | 23.3°C | -5.4°C | 42 mm | 76% | 3.5 m/s | 5.3 |
| 2007 | 9.6°C | 4.6°C | -0.3°C | 23.1°C | -7.9°C | 52 mm | 79% | 4.2 m/s | 3.8 |
| 2006 | 13.7°C | 7.2°C | 0.8°C | 22.9°C | -5.8°C | 45 mm | 75% | 3.6 m/s | 5.1 |
| 2005 | 12.1°C | 6.1°C | 0.1°C | 24.4°C | -2.6°C | 64 mm | 77% | 3.8 m/s | 4.7 |
| 2004 | 11.2°C | 5.8°C | 0.3°C | 21.9°C | -7.3°C | 54 mm | 82% | 4 m/s | 4.4 |
| 2003 | 9.9°C | 3.8°C | -2.2°C | 24.7°C | -18.2°C | 59 mm | 79% | 4 m/s | 4.8 |
| 2002 | 10.0°C | 5.2°C | 0.3°C | 23.8°C | -7.8°C | 94 mm | 84% | 3.6 m/s | 4.1 |
| 2001 | 12.4°C | 6.2°C | 0.0°C | 21.9°C | -4.7°C | 59 mm | 80% | 3.5 m/s | 4.7 |
| 2000 | 10.4°C | 5.0°C | -0.3°C | 21.0°C | -7.9°C | 95 mm | 78% | 3.5 m/s | 4 |
| 1999 | 12.1°C | 6.2°C | 0.2°C | 20.8°C | -4.1°C | 56 mm | 75% | 3.8 m/s | 4.8 |
| 1998 | 13.4°C | 7.1°C | 0.9°C | 19.0°C | -3.9°C | 33 mm | 70% | 3.3 m/s | 5.1 |
| 1997 | 9.8°C | 4.1°C | -1.5°C | 19.5°C | -9.1°C | 21 mm | 76% | 3.7 m/s | 4.8 |
| 1996 | 8.8°C | 3.6°C | -1.7°C | 20.2°C | -6.2°C | 68 mm | 77% | 4.3 m/s | 3.9 |
| 1995 | 8.9°C | 3.4°C | -2.0°C | 17.7°C | -7.9°C | 56 mm | 75% | 4.2 m/s | 3.7 |
| 1994 | 12.2°C | 6.0°C | -0.2°C | 23.4°C | -5.6°C | 63 mm | 74% | 4.5 m/s | 4.8 |
| 1993 | 11.3°C | 5.6°C | 0.0°C | 18.9°C | -3.7°C | 50 mm | 79% | 3.7 m/s | 3.9 |
| 1992 | 10.4°C | 4.9°C | -0.5°C | 21.3°C | -6.4°C | 51 mm | 78% | 3.4 m/s | 4 |
| 1991 | 12.9°C | 7.7°C | 2.5°C | 23.9°C | -4.6°C | 86 mm | 81% | 4.3 m/s | 3.9 |
| 1990 | 12.3°C | 6.9°C | 1.5°C | 25.9°C | -5.9°C | 29 mm | 77% | 3.7 m/s | 4.5 |
| 1989 | 9.9°C | 4.0°C | -1.8°C | 20.0°C | -6.6°C | 27 mm | 72% | 3.3 m/s | 4.5 |
| 1988 | 12.1°C | 5.9°C | -0.2°C | 19.4°C | -4.8°C | 29 mm | 75% | 3.8 m/s | 4.3 |
| 1987 | 13.8°C | 8.0°C | 2.3°C | 24.5°C | -6.6°C | 29 mm | 77% | 3.8 m/s | 4.5 |
| 1986 | 12.9°C | 6.9°C | 0.8°C | 24.7°C | -5.3°C | 51 mm | 78% | 3.7 m/s | 4.6 |
| 1985 | 12.6°C | 6.8°C | 1.0°C | 25.5°C | -9.0°C | 74 mm | 85% | 3.8 m/s | 5.1 |
| 1984 | 10.9°C | 5.9°C | 0.9°C | 20.4°C | -4.0°C | 52 mm | 83% | 3.8 m/s | 4.8 |
| 1983 | 8.8°C | 4.2°C | -0.5°C | 20.9°C | -4.1°C | 83 mm | 83% | 4.1 m/s | — |
| 1982 | 8.6°C | 2.8°C | -3.0°C | 19.5°C | -13.2°C | 67 mm | 80% | 4.7 m/s | — |
| 1981 | 12.5°C | 6.2°C | 0.0°C | 19.5°C | -5.8°C | 59 mm | 73% | 4.8 m/s | — |
Actual recorded April data for each year, 1981–2025 — sourced from NASA POWER.
The average high in April is around 11.3°C with lows near -0.1°C (mean 5.6°C), based on 45 years of NASA POWER data.
April averages 62 mm of rainfall in Waterloo, about average for rainfall. The wettest on record was 118 mm in 2017.
The hottest April reached 26.1°C in 2023. The coldest dipped to -18.2°C in 2003.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average April temperatures have risen by about 1.3°C. Daytime highs moved from 10.7°C to 12.3°C and overnight lows from -0.3°C to 0.7°C over the same span.
April is one of the cooler months of the year in Waterloo and about average for rainfall, so plan for around 11.3°C daytime highs and -0.1°C at night.
Not quite — April is the 6th coolest month in Waterloo, averaging 5.6°C.
For April in Waterloo, pack warm layers and a jacket for chilly mornings, with typical highs of 11.3°C and lows of -0.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in April averages 78% — quite humid.
Average wind speed in April is 3.9 m/s. The windiest April on record averaged 4.8 m/s (1981).
The wettest April on record was 2017 with 118 mm. On average, April sees 62 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 Waterloo 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.
