April is one of the cooler months of the year in New Castle, with average highs near 15.2°C and lows around 2.5°C (mean 8.9°C). It is about average for rainfall, averaging 86 mm of rainfall and 78% relative humidity across the period.
April is one of the cooler months of the year in New Castle. Across 45 years of records, the warmest April in New Castle was 2017 — when the month averaged 11.9°C — while the coldest was 1982 at 5.6°C. Typical April days reach 15.2°C with nights near 2.5°C. The long-term trend is warming, about 0.3°C per decade.
April is about average for rainfall in New Castle, averaging 86 mm of rainfall. The wettest April on record was 2011 with 161 mm, while the driest was 1982 at 34 mm.
Relative humidity in New Castle during April averages 78%. The most humid April was 2011 at 86%, and the least humid was 2006 at 73%.
April receives about 4.5 kWh/m²/day of solar energy in New Castle. The sunniest Aprils were 1989, 2006 and 2008 at 5 kWh/m²/day, and the cloudiest was 2011 at 3.3.
Average wind speed in New Castle during April is 0.2 m/s. The windiest Aprils were 2023, 2024 and 2025, among others at 0.2 m/s, while the calmest were 2019, 2020 and 2022, among others at 0.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 8.3°C | 8.3°C | 9.4°C | 9.2°C | 9.3°C | +1°C |
| Avg High | 14.5°C | 14.6°C | 15.8°C | 15.7°C | 15.6°C | +1.1°C |
| Avg Low | 2.0°C | 2.1°C | 2.9°C | 2.6°C | 2.9°C | +0.9°C |
| Avg Rain | 76 mm | 94 mm | 80 mm | 89 mm | 96 mm | +20 mm |
April temperatures in New Castle have risen by about 1.6°C between 1981–1985 and 2021–2025.
April has ranged from a record low of -10.9°C (1982) to a record high of 29.1°C (1985).
Rainfall in April is about average for rainfall, averaging 86 mm, with a wettest year of 161 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.4°C per decade while lows rose 0.2°C per decade, widening the gap between day and night.
A good time to visit New Castle
April is a good time to visit New Castle, with days averaging 15.2°C and nights around 2.5°C (mean 8.9°C, cooler than New Castle's yearly average) and higher rainfall. August and July 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 | 16.7°C | 10.0°C | 3.3°C | 28.3°C | -5.0°C | 121 mm | 74% | 0.2 m/s | 4.4 |
| 2024 | 17.6°C | 11.5°C | 5.4°C | 26.6°C | -3.0°C | 151 mm | 80% | 0.2 m/s | 4.3 |
| 2023 | 17.4°C | 10.3°C | 3.1°C | 28.3°C | -5.2°C | 65 mm | 74% | 0.2 m/s | 4.8 |
| 2022 | 13.6°C | 7.6°C | 1.6°C | 27.3°C | -5.1°C | 77 mm | 78% | 0.1 m/s | 4.4 |
| 2021 | 15.8°C | 9.5°C | 3.3°C | 26.5°C | -5.7°C | 60 mm | 74% | 0.2 m/s | 4.7 |
| 2020 | 12.7°C | 6.8°C | 1.0°C | 19.9°C | -5.3°C | 98 mm | 79% | 0.1 m/s | 4.6 |
| 2019 | 16.1°C | 10.0°C | 4.0°C | 23.3°C | -7.9°C | 93 mm | 82% | 0.1 m/s | 4 |
| 2018 | 11.8°C | 5.8°C | -0.3°C | 23.6°C | -4.5°C | 107 mm | 80% | 0.2 m/s | 4.3 |
| 2017 🔥 | 18.4°C | 11.9°C | 5.4°C | 27.7°C | -4.0°C | 83 mm | 80% | 0.1 m/s | 4.5 |
| 2016 | 14.8°C | 8.0°C | 1.1°C | 26.0°C | -6.7°C | 81 mm | 75% | 0.2 m/s | 4.5 |
| 2015 | 15.9°C | 9.2°C | 2.6°C | 23.7°C | -4.5°C | 84 mm | 77% | 0.2 m/s | 4.5 |
| 2014 | 15.8°C | 8.8°C | 1.9°C | 24.6°C | -6.6°C | 120 mm | 76% | 0.2 m/s | 4.6 |
| 2013 | 15.6°C | 8.9°C | 2.1°C | 25.5°C | -5.3°C | 69 mm | 78% | 0.1 m/s | 4.5 |
| 2012 | 15.3°C | 8.5°C | 1.7°C | 25.8°C | -4.0°C | 36 mm | 74% | 0.2 m/s | 4.8 |
| 2011 🌧️ | 15.0°C | 9.3°C | 3.6°C | 24.0°C | -3.7°C | 161 mm | 86% | 0.2 m/s | 3.3 |
| 2010 | 18.4°C | 11.2°C | 4.0°C | 27.4°C | -2.9°C | 53 mm | 74% | 0.2 m/s | 4.9 |
| 2009 | 15.2°C | 9.0°C | 2.8°C | 27.1°C | -5.2°C | 82 mm | 78% | 0.2 m/s | 4.7 |
| 2008 | 17.0°C | 10.4°C | 3.7°C | 24.3°C | -3.9°C | 50 mm | 80% | 0.1 m/s | 5 |
| 2007 | 12.5°C | 7.2°C | 1.9°C | 24.0°C | -5.0°C | 77 mm | 80% | 0.2 m/s | 3.7 |
| 2006 | 17.9°C | 10.7°C | 3.5°C | 26.4°C | -3.7°C | 65 mm | 73% | 0.2 m/s | 5 |
| 2005 | 15.5°C | 9.0°C | 2.4°C | 24.6°C | -1.4°C | 115 mm | 80% | 0.2 m/s | 4.7 |
| 2004 | 14.3°C | 8.6°C | 2.8°C | 24.9°C | -5.2°C | 99 mm | 81% | 0.1 m/s | 4.3 |
| 2003 | 17.1°C | 9.9°C | 2.7°C | 25.4°C | -5.3°C | 53 mm | 77% | 0.1 m/s | 4.9 |
| 2002 | 15.5°C | 9.6°C | 3.6°C | 28.1°C | -4.6°C | 87 mm | 78% | 0.1 m/s | 4.3 |
| 2001 | 17.7°C | 10.4°C | 3.2°C | 26.4°C | -4.1°C | 77 mm | 75% | 0.2 m/s | 4.8 |
| 2000 | 15.4°C | 8.8°C | 2.1°C | 24.6°C | -3.8°C | 93 mm | 76% | 0.2 m/s | 4.3 |
| 1999 | 16.9°C | 10.0°C | 3.2°C | 24.4°C | -2.5°C | 84 mm | 76% | 0.2 m/s | 4.8 |
| 1998 | 15.8°C | 9.3°C | 2.8°C | 21.1°C | -5.4°C | 143 mm | 76% | 0.2 m/s | 4.8 |
| 1997 | 12.6°C | 6.2°C | -0.1°C | 21.1°C | -6.0°C | 58 mm | 77% | 0.2 m/s | 4.9 |
| 1996 | 13.4°C | 7.1°C | 0.8°C | 22.3°C | -5.4°C | 134 mm | 81% | 0.1 m/s | 4.3 |
| 1995 | 13.0°C | 6.7°C | 0.3°C | 21.3°C | -6.6°C | 91 mm | 76% | 0.2 m/s | 4 |
| 1994 | 15.3°C | 8.7°C | 2.0°C | 25.7°C | -5.4°C | 107 mm | 80% | 0.2 m/s | 4.7 |
| 1993 | 14.0°C | 7.8°C | 1.5°C | 22.9°C | -4.7°C | 79 mm | 80% | 0.1 m/s | 3.7 |
| 1992 | 14.2°C | 8.2°C | 2.2°C | 25.0°C | -6.3°C | 70 mm | 79% | 0.1 m/s | 4.1 |
| 1991 | 16.0°C | 10.5°C | 5.1°C | 25.5°C | -5.3°C | 80 mm | 82% | 0.2 m/s | 4 |
| 1990 | 14.7°C | 8.7°C | 2.8°C | 29.0°C | -5.8°C | 90 mm | 76% | 0.2 m/s | 4.7 |
| 1989 | 13.2°C | 6.7°C | 0.1°C | 23.6°C | -6.5°C | 47 mm | 76% | 0.2 m/s | 5 |
| 1988 | 14.8°C | 8.3°C | 1.9°C | 24.3°C | -3.8°C | 60 mm | 76% | 0.1 m/s | 4.3 |
| 1987 | 14.9°C | 9.0°C | 3.0°C | 26.8°C | -9.5°C | 91 mm | 80% | 0.2 m/s | 4.7 |
| 1986 | 16.0°C | 9.5°C | 2.9°C | 27.7°C | -4.7°C | 45 mm | 79% | 0.2 m/s | 4.6 |
| 1985 | 16.8°C | 10.8°C | 4.8°C | 29.1°C | -6.0°C | 41 mm | 79% | 0.2 m/s | 4.9 |
| 1984 | 13.5°C | 7.8°C | 2.0°C | 23.7°C | -4.6°C | 77 mm | 83% | 0.1 m/s | 4.3 |
| 1983 | 12.5°C | 7.2°C | 1.8°C | 22.5°C | -5.1°C | 140 mm | 82% | 0.1 m/s | — |
| 1982 ❄️ | 12.4°C | 5.6°C | -1.2°C | 21.6°C | -10.9°C | 34 mm | 75% | 0.2 m/s | — |
| 1981 | 16.4°C | 9.5°C | 2.6°C | 23.0°C | -6.1°C | 149 mm | 76% | 0.2 m/s | — |
Actual recorded April data for each year, 1981–2025 — sourced from NASA POWER.
The average high in April is around 15.2°C with lows near 2.5°C (mean 8.9°C), based on 45 years of NASA POWER data.
April averages 86 mm of rainfall in New Castle, about average for rainfall. The wettest on record was 161 mm in 2011.
The hottest April reached 29.1°C in 1985. The coldest dipped to -10.9°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 14.3°C to 16.2°C and overnight lows from 2°C to 3.3°C over the same span.
April is one of the cooler months of the year in New Castle and about average for rainfall, so plan for around 15.2°C daytime highs and 2.5°C at night.
Not quite — April is the 6th coolest month in New Castle, averaging 8.9°C.
For April in New Castle, pack warm layers and a jacket for chilly mornings, with typical highs of 15.2°C and lows of 2.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in April averages 78% — quite humid.
Average wind speed in April is 0.2 m/s. The windiest April on record averaged 0.2 m/s (1981).
The wettest April on record was 2011 with 161 mm. On average, April sees 86 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 New Castle 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.
