May is one of the warmer months of the year in Norwalk, with average highs near 17.4°C and lows around 10.4°C (mean 13.9°C). It is about average for rainfall, averaging 102 mm of rainfall and 81% relative humidity across the period.
May is one of the warmer months of the year in Norwalk. Across 45 years of records, the warmest May in Norwalk was 2012 — when the month averaged 16.1°C — while the coldest was 1997 at 12.2°C. Typical May days reach 17.4°C with nights near 10.4°C. The long-term trend is warming, about 0.3°C per decade.
May is about average for rainfall in Norwalk, averaging 102 mm of rainfall. The wettest May on record was 1989 with 263 mm, while the driest was 2015 at 25 mm.
Relative humidity in Norwalk during May averages 81%. The most humid May was 1989 at 86%, and the least humid was 2023 at 74%.
May receives about 5.4 kWh/m²/day of solar energy in Norwalk. The sunniest May was 2023 at 6.8 kWh/m²/day, and the cloudiest was 1984 at 4.1.
Average wind speed in Norwalk during May is 2.1 m/s. The windiest May was 1997 at 2.7 m/s, while the calmest was 1982 at 1.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 13.6°C | 13.5°C | 13.7°C | 14.7°C | 14.3°C | +0.7°C |
| Avg High | 17.2°C | 17.1°C | 17.2°C | 18.0°C | 17.8°C | +0.6°C |
| Avg Low | 9.9°C | 9.8°C | 10.2°C | 11.3°C | 10.9°C | +1°C |
| Avg Rain | 121 mm | 98 mm | 94 mm | 98 mm | 103 mm | -18 mm |
May temperatures in Norwalk have risen by about 1.3°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 2.2°C (2020) to a record high of 30.3°C (2022).
Rainfall in May is about average for rainfall, averaging 102 mm, with a wettest year of 263 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.2°C per decade while lows rose 0.4°C per decade, narrowing the gap between day and night.
A good time to visit Norwalk
May is a good time to visit Norwalk, with days averaging 17.4°C and nights around 10.4°C (mean 13.9°C, warmer than Norwalk's yearly average) and higher rainfall. August and July are marginally more temperate, but May still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 17.6°C | 14.5°C | 11.4°C | 21.3°C | 8.0°C | 169 mm | 84% | 2.2 m/s | 4.5 |
| 2024 | 18.5°C | 15.4°C | 12.2°C | 23.8°C | 7.8°C | 120 mm | 84% | 2 m/s | 5.5 |
| 2023 | 18.1°C | 14.3°C | 10.6°C | 24.0°C | 5.8°C | 56 mm | 74% | 2.1 m/s | 6.8 |
| 2022 | 18.4°C | 14.8°C | 11.2°C | 30.3°C | 5.8°C | 87 mm | 81% | 2.2 m/s | 5.5 |
| 2021 | 18.1°C | 14.4°C | 10.7°C | 26.1°C | 4.7°C | 135 mm | 77% | 2.2 m/s | 5.6 |
| 2020 | 16.2°C | 12.6°C | 9.0°C | 22.6°C | 2.2°C | 50 mm | 78% | 2.4 m/s | 6.2 |
| 2019 | 17.2°C | 14.0°C | 10.8°C | 24.3°C | 5.4°C | 143 mm | 84% | 2.2 m/s | 5 |
| 2018 | 18.8°C | 15.4°C | 11.9°C | 25.5°C | 5.4°C | 89 mm | 84% | 1.8 m/s | 5.2 |
| 2017 | 16.5°C | 13.5°C | 10.4°C | 25.5°C | 6.0°C | 143 mm | 82% | 2.3 m/s | 4.9 |
| 2016 | 17.3°C | 14.0°C | 10.6°C | 25.6°C | 5.2°C | 101 mm | 82% | 2.1 m/s | 5.1 |
| 2015 | 19.2°C | 15.5°C | 11.7°C | 24.8°C | 6.6°C | 25 mm | 81% | 2 m/s | 6.1 |
| 2014 | 17.7°C | 14.3°C | 11.0°C | 23.6°C | 6.4°C | 88 mm | 81% | 1.9 m/s | 5.4 |
| 2013 | 17.5°C | 14.0°C | 10.4°C | 26.3°C | 5.0°C | 102 mm | 83% | 2.2 m/s | 5.6 |
| 2012 🔥 | 19.2°C | 16.1°C | 13.1°C | 27.9°C | 8.3°C | 112 mm | 84% | 1.8 m/s | 4.9 |
| 2011 | 18.2°C | 15.0°C | 11.8°C | 26.2°C | 6.7°C | 104 mm | 85% | 2 m/s | 5 |
| 2010 | 18.7°C | 14.9°C | 11.1°C | 26.9°C | 4.6°C | 72 mm | 81% | 2.1 m/s | 6 |
| 2009 | 17.3°C | 14.1°C | 10.9°C | 23.4°C | 6.5°C | 110 mm | 83% | 2 m/s | 5 |
| 2008 | 16.5°C | 13.0°C | 9.5°C | 21.6°C | 4.7°C | 82 mm | 78% | 2.5 m/s | 5.5 |
| 2007 | 18.4°C | 14.5°C | 10.5°C | 25.4°C | 4.8°C | 39 mm | 78% | 1.9 m/s | 6.6 |
| 2006 | 17.4°C | 14.0°C | 10.6°C | 24.0°C | 6.7°C | 136 mm | 81% | 2.2 m/s | 5.1 |
| 2005 | 15.5°C | 12.3°C | 9.0°C | 20.3°C | 5.2°C | 65 mm | 80% | 2.2 m/s | 5.5 |
| 2004 | 18.6°C | 14.9°C | 11.2°C | 24.7°C | 5.9°C | 88 mm | 85% | 1.9 m/s | 5.4 |
| 2003 | 15.7°C | 12.4°C | 9.2°C | 21.8°C | 6.0°C | 123 mm | 84% | 1.9 m/s | 4.5 |
| 2002 | 16.9°C | 13.2°C | 9.5°C | 22.2°C | 4.7°C | 112 mm | 77% | 2.4 m/s | 5.7 |
| 2001 | 18.0°C | 14.3°C | 10.7°C | 27.1°C | 5.2°C | 87 mm | 78% | 2.1 m/s | 5.5 |
| 2000 | 17.7°C | 14.2°C | 10.8°C | 25.6°C | 4.6°C | 98 mm | 82% | 2.1 m/s | 5.2 |
| 1999 | 18.2°C | 14.5°C | 10.8°C | 27.1°C | 5.9°C | 83 mm | 77% | 1.9 m/s | 5.7 |
| 1998 | 18.1°C | 14.5°C | 10.9°C | 25.0°C | 4.8°C | 176 mm | 85% | 2.2 m/s | 5.7 |
| 1997 ❄️ | 15.7°C | 12.2°C | 8.7°C | 21.9°C | 3.8°C | 78 mm | 78% | 2.7 m/s | 5.5 |
| 1996 | 16.2°C | 12.6°C | 9.0°C | 24.9°C | 3.5°C | 76 mm | 81% | 2.1 m/s | 5.2 |
| 1995 | 16.3°C | 12.9°C | 9.4°C | 22.9°C | 4.6°C | 66 mm | 79% | 2 m/s | 4.9 |
| 1994 | 16.5°C | 12.7°C | 8.8°C | 24.8°C | 5.2°C | 91 mm | 80% | 2.2 m/s | 5.6 |
| 1993 | 18.0°C | 14.3°C | 10.5°C | 22.6°C | 6.5°C | 40 mm | 79% | 1.9 m/s | 5.7 |
| 1992 | 16.7°C | 12.5°C | 8.4°C | 26.2°C | 3.1°C | 85 mm | 77% | 2 m/s | 5.5 |
| 1991 | 19.6°C | 16.0°C | 12.3°C | 26.3°C | 7.4°C | 89 mm | 81% | 2 m/s | 6.1 |
| 1990 | 15.8°C | 12.5°C | 9.2°C | 19.9°C | 5.2°C | 191 mm | 81% | 2.4 m/s | 5 |
| 1989 🌧️ | 16.7°C | 13.4°C | 10.1°C | 22.9°C | 5.6°C | 263 mm | 86% | 2.3 m/s | 4.8 |
| 1988 | 17.3°C | 13.8°C | 10.4°C | 25.3°C | 5.2°C | 97 mm | 85% | 1.9 m/s | 5.2 |
| 1987 | 17.0°C | 13.4°C | 9.7°C | 26.8°C | 4.8°C | 51 mm | 83% | 2.2 m/s | 5.3 |
| 1986 | 18.4°C | 14.5°C | 10.7°C | 25.7°C | 3.0°C | 28 mm | 79% | 2.1 m/s | 6.2 |
| 1985 | 18.1°C | 14.3°C | 10.5°C | 23.7°C | 3.7°C | 136 mm | 79% | 2.3 m/s | 5.7 |
| 1984 | 15.5°C | 12.3°C | 9.1°C | 20.6°C | 4.6°C | 239 mm | 84% | 2.2 m/s | 4.1 |
| 1983 | 15.7°C | 12.3°C | 8.9°C | 21.0°C | 3.6°C | 123 mm | 85% | 2.3 m/s | — |
| 1982 | 18.1°C | 14.1°C | 10.1°C | 23.4°C | 6.8°C | 75 mm | 80% | 1.6 m/s | — |
| 1981 | 18.0°C | 13.9°C | 9.8°C | 24.2°C | 4.3°C | 76 mm | 77% | 2.1 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 17.4°C with lows near 10.4°C (mean 13.9°C), based on 45 years of NASA POWER data.
May averages 102 mm of rainfall in Norwalk, about average for rainfall. The wettest on record was 263 mm in 1989.
The hottest May reached 30.3°C in 2022. The coldest dipped to 2.2°C in 2020.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 1.3°C. Daytime highs moved from 17.1°C to 18.1°C and overnight lows from 9.7°C to 11.2°C over the same span.
May is one of the warmer months of the year in Norwalk and about average for rainfall, so plan for around 17.4°C daytime highs and 10.4°C at night.
Not quite — May is the 7th coolest month in Norwalk, averaging 13.9°C.
For May in Norwalk, pack light layers you can adjust through the day, with typical highs of 17.4°C and lows of 10.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 81% — quite humid.
Average wind speed in May is 2.1 m/s. The windiest May on record averaged 2.7 m/s (1997).
The wettest May on record was 1989 with 263 mm. On average, May sees 102 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 Norwalk behaves each May, 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 May specifically, along with year-by-year records and how the month has changed over the decades.
