May is one of the warmer months of the year in Lancaster, with average highs near 27.1°C and lows around 9.8°C (mean 18.5°C). It is one of the drier months, averaging 7 mm of rainfall and 50% relative humidity across the period.
May is one of the warmer months of the year in Lancaster. Across 45 years of records, the warmest May in Lancaster was 1997 — when the month averaged 23.2°C — while the coldest was 1998 at 13.3°C. Typical May days reach 27.1°C with nights near 9.8°C. The long-term May temperature trend is broadly flat.
May is one of the drier months in Lancaster, averaging 7 mm of rainfall. The wettest May on record was 1998 with 70 mm, while the driest were 1984, 2004 and 2007 at 0 mm.
Relative humidity in Lancaster during May averages 50%. The most humid May was 1998 at 72%, and the least humid was 1984 at 31%.
May receives about 7.4 kWh/m²/day of solar energy in Lancaster. The sunniest Mays were 2012, 2020 and 2022, among others at 8 kWh/m²/day, and the cloudiest was 2019 at 6.5.
Average wind speed in Lancaster during May is 2.4 m/s. The windiest May was 1984 at 3 m/s, while the calmest was 1992 at 1.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 18.5°C | 17.6°C | 19.6°C | 17.8°C | 18.8°C | +0.3°C |
| Avg High | 27.4°C | 26.0°C | 28.6°C | 26.1°C | 27.4°C | 0°C |
| Avg Low | 9.6°C | 9.3°C | 10.6°C | 9.4°C | 10.3°C | +0.7°C |
| Avg Rain | 3 mm | 12 mm | 7 mm | 9 mm | 5 mm | +1 mm |
May temperatures in Lancaster have stayed relatively stable across the record.
May has ranged from a record low of 1.2°C (1991) to a record high of 40.1°C (2003).
Rainfall in May is one of the drier months, averaging 7 mm, with a wettest year of 70 mm.
Daytime highs and overnight lows have shifted differently — highs fell about 0.1°C per decade while lows rose 0.1°C per decade, narrowing the gap between day and night.
One of the best times to visit Lancaster
May is one of the best times to visit Lancaster. Expect days averaging 27.1°C and nights around 9.8°C (mean 18.5°C) — warmer than Lancaster's yearly average — with low rainfall (7 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 28.2°C | 19.8°C | 11.4°C | 38.3°C | 6.1°C | 6 mm | 52% | 2.1 m/s | 7.2 |
| 2024 | 26.0°C | 17.5°C | 9.1°C | 31.1°C | 3.2°C | 3 mm | 60% | 2.3 m/s | 7.3 |
| 2023 | 23.8°C | 17.0°C | 10.2°C | 32.1°C | 5.0°C | 15 mm | 68% | 2.4 m/s | 6.7 |
| 2022 | 28.8°C | 19.3°C | 9.9°C | 35.9°C | 2.5°C | 0 mm | 41% | 2.4 m/s | 8 |
| 2021 | 29.1°C | 19.8°C | 10.4°C | 36.7°C | 4.2°C | 1 mm | 41% | 2.3 m/s | 7.9 |
| 2020 | 28.3°C | 19.4°C | 10.5°C | 36.2°C | 6.0°C | 3 mm | 50% | 2.3 m/s | 8 |
| 2019 | 22.3°C | 15.3°C | 8.4°C | 28.8°C | 5.2°C | 40 mm | 67% | 2.3 m/s | 6.5 |
| 2018 | 26.2°C | 18.3°C | 10.4°C | 34.7°C | 7.1°C | 4 mm | 57% | 2.4 m/s | 6.9 |
| 2017 | 26.8°C | 18.5°C | 10.2°C | 35.9°C | 4.1°C | 6 mm | 52% | 2.3 m/s | 7.3 |
| 2016 | 25.8°C | 17.7°C | 9.6°C | 36.2°C | 5.5°C | 6 mm | 57% | 2.3 m/s | 7 |
| 2015 | 24.6°C | 17.1°C | 9.6°C | 34.8°C | 5.4°C | 14 mm | 56% | 2.5 m/s | 6.8 |
| 2014 | 29.2°C | 20.0°C | 10.9°C | 36.1°C | 6.2°C | 2 mm | 36% | 2.5 m/s | 7.8 |
| 2013 | 28.4°C | 19.6°C | 10.7°C | 37.2°C | 6.4°C | 9 mm | 40% | 2.6 m/s | 7.7 |
| 2012 | 29.7°C | 19.8°C | 9.8°C | 39.0°C | 5.0°C | 1 mm | 40% | 2.4 m/s | 8 |
| 2011 | 23.8°C | 15.5°C | 7.3°C | 31.9°C | 2.4°C | 10 mm | 54% | 2.5 m/s | 7.7 |
| 2010 | 24.1°C | 15.7°C | 7.3°C | 31.4°C | 2.8°C | 3 mm | 51% | 2.5 m/s | 7.8 |
| 2009 | 31.0°C | 21.5°C | 12.1°C | 37.2°C | 8.5°C | 1 mm | 43% | 2.4 m/s | 7.7 |
| 2008 | 26.0°C | 17.7°C | 9.4°C | 38.6°C | 3.6°C | 9 mm | 47% | 2.5 m/s | 7.4 |
| 2007 | 29.0°C | 19.5°C | 9.9°C | 32.9°C | 5.3°C | 0 mm | 37% | 2.4 m/s | 7.9 |
| 2006 | 28.8°C | 19.9°C | 11.1°C | 35.9°C | 5.8°C | 11 mm | 53% | 2.1 m/s | 7.3 |
| 2005 | 26.4°C | 18.1°C | 9.9°C | 34.7°C | 4.2°C | 14 mm | 62% | 2.1 m/s | 7.5 |
| 2004 | 28.8°C | 19.7°C | 10.6°C | 36.1°C | 5.9°C | 0 mm | 40% | 2.4 m/s | 8 |
| 2003 | 26.7°C | 18.2°C | 9.7°C | 40.1°C | 2.3°C | 25 mm | 52% | 2.2 m/s | 7.2 |
| 2002 | 28.2°C | 18.6°C | 9.0°C | 37.6°C | 3.7°C | 3 mm | 42% | 2.2 m/s | 7.8 |
| 2001 | 31.8°C | 22.4°C | 12.9°C | 39.8°C | 6.7°C | 1 mm | 44% | 2 m/s | 7.7 |
| 2000 | 28.8°C | 19.9°C | 11.1°C | 37.5°C | 3.9°C | 5 mm | 47% | 2.5 m/s | 7.6 |
| 1999 | 26.8°C | 17.6°C | 8.4°C | 33.9°C | 4.1°C | 2 mm | 49% | 2.4 m/s | 7.4 |
| 1998 ❄️ 🌧️ | 19.9°C | 13.3°C | 6.8°C | 25.2°C | 4.3°C | 70 mm | 72% | 2.3 m/s | 6.6 |
| 1997 🔥 | 32.6°C | 23.2°C | 13.7°C | 37.9°C | 8.0°C | 1 mm | 37% | 2.3 m/s | 7.8 |
| 1996 | 28.1°C | 19.1°C | 10.1°C | 35.4°C | 6.0°C | 1 mm | 45% | 2.5 m/s | 7.8 |
| 1995 | 22.1°C | 15.0°C | 8.0°C | 30.6°C | 3.3°C | 8 mm | 67% | 2.4 m/s | 6.6 |
| 1994 | 26.0°C | 17.4°C | 8.9°C | 33.7°C | 5.0°C | 11 mm | 54% | 2.2 m/s | 6.8 |
| 1993 | 25.6°C | 17.6°C | 9.6°C | 30.3°C | 4.0°C | 1 mm | 58% | 2.5 m/s | 7.5 |
| 1992 | 28.3°C | 20.0°C | 11.7°C | 33.1°C | 7.2°C | 3 mm | 58% | 1.9 m/s | 7 |
| 1991 | 24.4°C | 15.7°C | 7.0°C | 32.0°C | 1.2°C | 1 mm | 52% | 2.5 m/s | 7.4 |
| 1990 | 26.6°C | 17.5°C | 8.4°C | 34.5°C | 5.6°C | 17 mm | 43% | 2.6 m/s | 7.3 |
| 1989 | 27.7°C | 18.5°C | 9.4°C | 34.4°C | 5.4°C | 5 mm | 42% | 2.4 m/s | 7.2 |
| 1988 | 26.7°C | 17.9°C | 9.0°C | 34.7°C | 1.7°C | 4 mm | 44% | 2.5 m/s | 7.2 |
| 1987 | 27.8°C | 19.5°C | 11.2°C | 34.1°C | 5.7°C | 7 mm | 43% | 2.3 m/s | 6.8 |
| 1986 | 27.5°C | 18.5°C | 9.5°C | 34.7°C | 3.6°C | 1 mm | 44% | 2.3 m/s | 7.6 |
| 1985 | 27.0°C | 17.8°C | 8.7°C | 33.0°C | 3.7°C | 3 mm | 42% | 2.3 m/s | 7.3 |
| 1984 | 31.7°C | 21.9°C | 12.0°C | 39.0°C | 4.7°C | 0 mm | 31% | 3 m/s | 7 |
| 1983 | 25.4°C | 17.0°C | 8.5°C | 34.4°C | 3.3°C | 2 mm | 59% | 2.4 m/s | — |
| 1982 | 26.3°C | 17.8°C | 9.3°C | 34.1°C | 3.4°C | 6 mm | 54% | 2.2 m/s | — |
| 1981 | 26.9°C | 18.0°C | 9.1°C | 33.5°C | 4.0°C | 3 mm | 45% | 2.4 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 27.1°C with lows near 9.8°C (mean 18.5°C), based on 45 years of NASA POWER data.
May averages 7 mm of rainfall in Lancaster, one of the drier months. The wettest on record was 70 mm in 1998.
The hottest May reached 40.1°C in 2003. The coldest dipped to 1.2°C in 1991.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have risen by about 0.2°C — but days and nights have moved in opposite directions. Overnight lows rose from 9.5°C to 10.2°C while daytime highs eased from 27.5°C to 27.2°C, narrowing the gap between day and night.
May is one of the warmer months of the year in Lancaster and one of the drier months, so plan for around 27.1°C daytime highs and 9.8°C at night.
Not quite — May is the 7th coolest month in Lancaster, averaging 18.5°C.
For May in Lancaster, pack light layers you can adjust through the day, with typical highs of 27.1°C and lows of 9.8°C.
Relative humidity in May averages 50% — relatively dry.
Average wind speed in May is 2.4 m/s. The windiest May on record averaged 3 m/s (1984).
The wettest May on record was 1998 with 70 mm. On average, May sees 7 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 Lancaster 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.
