May is one of the cooler months of the year in Santa Ana, with average highs near 18.7°C and lows around 14.6°C (mean 16.7°C). It is one of the drier months, averaging 6 mm of rainfall and 77% relative humidity across the period.
May is one of the cooler months of the year in Santa Ana. Across 45 years of records, the warmest May in Santa Ana was 1984 — when the month averaged 19.3°C — while the coldest was 1995 at 14.9°C. Typical May days reach 18.7°C with nights near 14.6°C. The long-term trend is cooling, about 0.3°C per decade.
May is one of the drier months in Santa Ana, averaging 6 mm of rainfall. The wettest May on record was 1998 with 53 mm, while the driest were 1997, 2004 and 2007, among others at 0 mm.
Relative humidity in Santa Ana during May averages 77%. The most humid May was 2024 at 84%, and the least humid was 1984 at 66%.
May receives about 6.8 kWh/m²/day of solar energy in Santa Ana. The sunniest Mays were 2014 and 2020 at 7.7 kWh/m²/day, and the cloudiest were 1994, 1995 and 2023 at 5.8.
Average wind speed in Santa Ana during May is 2.8 m/s. The windiest May was 1991 at 3.6 m/s, while the calmest was 2001 at 2.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.3°C | 16.7°C | 16.5°C | 16.4°C | 16.3°C | -1°C |
| Avg High | 19.8°C | 18.8°C | 18.5°C | 18.4°C | 18.1°C | -1.7°C |
| Avg Low | 14.8°C | 14.7°C | 14.4°C | 14.4°C | 14.5°C | -0.3°C |
| Avg Rain | 2 mm | 9 mm | 5 mm | 10 mm | 4 mm | +2 mm |
May temperatures in Santa Ana have fallen by about 1.3°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 11.2°C (1988) to a record high of 31.7°C (2014).
Rainfall in May is one of the drier months, averaging 6 mm, with a wettest year of 53 mm.
Daytime highs and overnight lows have shifted differently — highs fell about 0.4°C per decade while lows fell 0.1°C per decade, narrowing the gap between day and night.
A good time to visit Santa Ana
May is a good time to visit Santa Ana, with days averaging 18.7°C and nights around 14.6°C (mean 16.7°C, close to Santa Ana's yearly average) and low rainfall. August and September 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 | 18.9°C | 17.0°C | 15.1°C | 23.2°C | 12.7°C | 3 mm | 80% | 2.6 m/s | 6.7 |
| 2024 | 17.0°C | 15.3°C | 13.6°C | 17.8°C | 12.5°C | 3 mm | 84% | 2.7 m/s | 6.3 |
| 2023 | 16.6°C | 15.2°C | 13.8°C | 18.1°C | 12.1°C | 12 mm | 84% | 2.8 m/s | 5.8 |
| 2022 | 18.4°C | 16.4°C | 14.4°C | 24.1°C | 13.2°C | 0 mm | 78% | 2.7 m/s | 7.2 |
| 2021 | 18.1°C | 16.1°C | 14.1°C | 23.0°C | 12.5°C | 2 mm | 80% | 2.7 m/s | 7.1 |
| 2020 | 19.8°C | 17.9°C | 16.0°C | 24.1°C | 14.5°C | 3 mm | 80% | 2.7 m/s | 7.7 |
| 2019 | 17.1°C | 15.6°C | 14.0°C | 18.6°C | 12.4°C | 33 mm | 84% | 3.1 m/s | 6.2 |
| 2018 | 17.9°C | 16.2°C | 14.4°C | 22.8°C | 12.3°C | 4 mm | 80% | 2.9 m/s | 6.4 |
| 2017 | 18.3°C | 16.3°C | 14.4°C | 23.8°C | 12.1°C | 9 mm | 79% | 2.8 m/s | 6.8 |
| 2016 | 17.9°C | 16.2°C | 14.5°C | 19.7°C | 13.4°C | 9 mm | 81% | 2.9 m/s | 6.5 |
| 2015 | 18.1°C | 16.4°C | 14.7°C | 23.5°C | 13.3°C | 18 mm | 77% | 2.9 m/s | 6.2 |
| 2014 | 21.6°C | 18.9°C | 16.2°C | 31.7°C | 13.7°C | 0 mm | 70% | 2.7 m/s | 7.7 |
| 2013 | 19.7°C | 17.4°C | 15.1°C | 26.1°C | 13.3°C | 10 mm | 77% | 2.8 m/s | 7.4 |
| 2012 | 18.2°C | 16.1°C | 13.9°C | 22.8°C | 12.3°C | 1 mm | 79% | 2.6 m/s | 7.3 |
| 2011 | 17.9°C | 15.8°C | 13.7°C | 26.3°C | 12.4°C | 16 mm | 75% | 3.2 m/s | 7.3 |
| 2010 | 17.4°C | 15.3°C | 13.2°C | 21.4°C | 12.0°C | 1 mm | 78% | 3 m/s | 7.6 |
| 2009 | 18.4°C | 16.4°C | 14.3°C | 24.2°C | 13.0°C | 0 mm | 80% | 2.4 m/s | 6.9 |
| 2008 | 18.5°C | 16.4°C | 14.2°C | 26.4°C | 12.4°C | 4 mm | 75% | 2.8 m/s | 6.9 |
| 2007 | 17.7°C | 15.5°C | 13.2°C | 27.5°C | 11.5°C | 0 mm | 76% | 2.7 m/s | 7 |
| 2006 | 18.3°C | 16.5°C | 14.6°C | 21.8°C | 13.4°C | 21 mm | 81% | 2.4 m/s | 6.4 |
| 2005 | 19.1°C | 17.2°C | 15.4°C | 22.8°C | 13.9°C | 5 mm | 81% | 2.5 m/s | 7.2 |
| 2004 | 20.3°C | 18.1°C | 15.8°C | 27.7°C | 14.0°C | 0 mm | 73% | 2.8 m/s | 7.5 |
| 2003 | 17.4°C | 15.5°C | 13.7°C | 21.5°C | 12.0°C | 17 mm | 81% | 2.6 m/s | 6.6 |
| 2002 | 17.5°C | 15.4°C | 13.3°C | 23.5°C | 12.0°C | 2 mm | 77% | 2.7 m/s | 7.1 |
| 2001 | 18.7°C | 16.7°C | 14.8°C | 24.1°C | 12.2°C | 1 mm | 82% | 2.2 m/s | 6.3 |
| 2000 | 19.0°C | 17.0°C | 15.0°C | 22.7°C | 13.6°C | 2 mm | 79% | 2.8 m/s | 6.9 |
| 1999 | 17.0°C | 15.2°C | 13.3°C | 20.0°C | 11.2°C | 0 mm | 78% | 2.7 m/s | 6.6 |
| 1998 🌧️ | 17.4°C | 15.9°C | 14.4°C | 19.2°C | 12.4°C | 53 mm | 80% | 3.2 m/s | 6.6 |
| 1997 | 21.4°C | 19.1°C | 16.8°C | 26.1°C | 15.0°C | 0 mm | 78% | 2.3 m/s | 7.2 |
| 1996 | 19.7°C | 17.7°C | 15.6°C | 22.1°C | 13.9°C | 1 mm | 77% | 3 m/s | 7.5 |
| 1995 ❄️ | 16.5°C | 14.9°C | 13.3°C | 19.7°C | 11.4°C | 8 mm | 83% | 3.2 m/s | 5.8 |
| 1994 | 17.5°C | 15.7°C | 13.8°C | 21.1°C | 12.5°C | 5 mm | 79% | 2.7 m/s | 5.8 |
| 1993 | 20.3°C | 18.0°C | 15.7°C | 27.1°C | 14.4°C | 0 mm | 77% | 3 m/s | 7 |
| 1992 | 20.3°C | 18.2°C | 16.1°C | 21.4°C | 15.1°C | 2 mm | 81% | 2.5 m/s | 6.1 |
| 1991 | 17.6°C | 15.3°C | 13.1°C | 22.8°C | 11.6°C | 0 mm | 75% | 3.6 m/s | 6.8 |
| 1990 | 19.8°C | 17.3°C | 14.8°C | 27.9°C | 13.6°C | 21 mm | 73% | 3.5 m/s | 6.8 |
| 1989 | 19.5°C | 17.2°C | 14.9°C | 22.5°C | 13.2°C | 2 mm | 73% | 3.1 m/s | 6.7 |
| 1988 | 19.8°C | 17.2°C | 14.7°C | 25.3°C | 11.2°C | 1 mm | 70% | 3.2 m/s | 6.8 |
| 1987 | 20.7°C | 18.2°C | 15.7°C | 25.5°C | 13.6°C | 2 mm | 70% | 2.7 m/s | 6.2 |
| 1986 | 19.5°C | 17.0°C | 14.5°C | 26.4°C | 12.2°C | 0 mm | 72% | 2.7 m/s | 7.1 |
| 1985 | 18.6°C | 16.3°C | 13.9°C | 21.2°C | 12.1°C | 3 mm | 74% | 2.8 m/s | 6.6 |
| 1984 🔥 | 22.3°C | 19.3°C | 16.2°C | 28.1°C | 13.3°C | 0 mm | 66% | 3 m/s | 6.5 |
| 1983 | 19.7°C | 17.2°C | 14.8°C | 24.6°C | 12.1°C | 3 mm | 77% | 3 m/s | — |
| 1982 | 18.3°C | 16.2°C | 14.1°C | 21.0°C | 13.0°C | 5 mm | 78% | 2.9 m/s | — |
| 1981 | 20.0°C | 17.4°C | 14.7°C | 24.7°C | 13.6°C | 2 mm | 72% | 3 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 18.7°C with lows near 14.6°C (mean 16.7°C), based on 45 years of NASA POWER data.
May averages 6 mm of rainfall in Santa Ana, one of the drier months. The wettest on record was 53 mm in 1998.
The hottest May reached 31.7°C in 2014. The coldest dipped to 11.2°C in 1988.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have fallen by about 1.3°C. Daytime highs moved from 19.8°C to 17.8°C and overnight lows from 14.7°C to 14.2°C over the same span.
May is one of the cooler months of the year in Santa Ana and one of the drier months, so plan for around 18.7°C daytime highs and 14.6°C at night.
Not quite — May is the 6th coolest month in Santa Ana, averaging 16.7°C.
For May in Santa Ana, pack light layers you can adjust through the day, with typical highs of 18.7°C and lows of 14.6°C.
Relative humidity in May averages 77% — quite humid.
Average wind speed in May is 2.8 m/s. The windiest May on record averaged 3.6 m/s (1991).
The wettest May on record was 1998 with 53 mm. On average, May sees 6 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 Santa Ana 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.
