April is one of the warmer months of the year in Siwan, with average highs near 40.7°C and lows around 23.5°C (mean 32.1°C). It is one of the drier months, averaging 13 mm of rainfall and 23% relative humidity across the period.
April is one of the warmer months of the year in Siwan. Across 45 years of records, the warmest April in Siwan was 2016 — when the month averaged 34.9°C — while the coldest were 1983 and 1997 at 29.9°C. Typical April days reach 40.7°C with nights near 23.5°C. The long-term April temperature trend is broadly flat.
April is one of the drier months in Siwan, averaging 13 mm of rainfall. The wettest April on record was 1982 with 59 mm, while the driest were 1999 and 2010 at 0 mm.
Relative humidity in Siwan during April averages 23%. The most humid April was 2015 at 37%, and the least humid was 1999 at 11%.
April receives about 6.5 kWh/m²/day of solar energy in Siwan. The sunniest Aprils were 1989 and 1999 at 7.3 kWh/m²/day, and the cloudiest was 2025 at 5.6.
Average wind speed in Siwan during April is 2.4 m/s. The windiest April was 2024 at 3.5 m/s, while the calmest was 2008 at 1.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 31.9°C | 31.9°C | 32.2°C | 32.4°C | 32.2°C | +0.3°C |
| Avg High | 40.7°C | 40.9°C | 40.7°C | 40.6°C | 40.5°C | -0.2°C |
| Avg Low | 23.0°C | 22.9°C | 23.6°C | 24.2°C | 23.8°C | +0.8°C |
| Avg Rain | 16 mm | 6 mm | 15 mm | 16 mm | 14 mm | -2 mm |
April temperatures in Siwan have risen by about 0.9°C between 1981–1985 and 2021–2025.
April has ranged from a record low of 14.3°C (1988) to a record high of 47.1°C (1999).
Rainfall in April is one of the drier months, averaging 13 mm, with a wettest year of 59 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0°C per decade while lows rose 0.3°C per decade, narrowing the gap between day and night.
A good time to visit Siwan
April is a good time to visit Siwan, with days averaging 40.7°C and nights around 23.5°C (mean 32.1°C, warmer than Siwan's yearly average) and low rainfall. November and February 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 | 40.0°C | 31.9°C | 23.8°C | 45.3°C | 18.3°C | 27 mm | 31% | 2.4 m/s | 5.6 |
| 2024 | 41.7°C | 33.5°C | 25.3°C | 44.8°C | 21.3°C | 1 mm | 20% | 3.5 m/s | 6.4 |
| 2023 | 39.2°C | 31.1°C | 22.9°C | 44.6°C | 19.1°C | 15 mm | 29% | 2.7 m/s | 6.1 |
| 2022 | 42.6°C | 33.6°C | 24.5°C | 44.9°C | 21.8°C | 4 mm | 24% | 2.3 m/s | 6.2 |
| 2021 | 41.2°C | 32.3°C | 23.5°C | 43.7°C | 17.8°C | 8 mm | 16% | 2.3 m/s | 6.3 |
| 2020 | 38.4°C | 30.5°C | 22.6°C | 41.9°C | 17.0°C | 29 mm | 35% | 2.2 m/s | 6.2 |
| 2019 | 41.0°C | 32.7°C | 24.4°C | 45.9°C | 19.9°C | 15 mm | 28% | 2.2 m/s | 6.1 |
| 2018 | 39.6°C | 31.8°C | 24.0°C | 43.2°C | 21.3°C | 49 mm | 32% | 2.4 m/s | 5.9 |
| 2017 | 41.9°C | 33.4°C | 25.0°C | 43.9°C | 19.8°C | 5 mm | 24% | 2.4 m/s | 6.1 |
| 2016 🔥 | 43.4°C | 34.9°C | 26.4°C | 45.1°C | 22.3°C | 0 mm | 17% | 3.1 m/s | 6.6 |
| 2015 | 37.9°C | 30.7°C | 23.5°C | 42.7°C | 19.3°C | 25 mm | 37% | 2.2 m/s | 5.9 |
| 2014 | 40.9°C | 32.2°C | 23.5°C | 44.3°C | 18.4°C | 0 mm | 20% | 2.4 m/s | 7 |
| 2013 | 39.3°C | 31.3°C | 23.4°C | 43.8°C | 18.1°C | 20 mm | 30% | 2.4 m/s | 6.4 |
| 2012 | 40.4°C | 32.2°C | 24.0°C | 43.0°C | 20.2°C | 12 mm | 25% | 2.4 m/s | 6.6 |
| 2011 | 38.3°C | 30.6°C | 22.8°C | 41.2°C | 19.4°C | 31 mm | 30% | 1.9 m/s | 6.3 |
| 2010 | 43.0°C | 33.9°C | 24.9°C | 45.4°C | 21.0°C | 0 mm | 16% | 2.3 m/s | 6.7 |
| 2009 | 41.2°C | 32.2°C | 23.3°C | 44.0°C | 18.4°C | 0 mm | 17% | 2.2 m/s | 6.9 |
| 2008 | 39.7°C | 31.0°C | 22.4°C | 44.3°C | 17.7°C | 29 mm | 29% | 1.8 m/s | 6.9 |
| 2007 | 40.2°C | 32.2°C | 24.1°C | 42.9°C | 17.3°C | 17 mm | 30% | 2 m/s | 6.4 |
| 2006 | 39.8°C | 31.8°C | 23.7°C | 42.9°C | 20.3°C | 17 mm | 27% | 2 m/s | 6.4 |
| 2005 | 40.2°C | 31.6°C | 23.0°C | 44.1°C | 16.7°C | 7 mm | 19% | 1.9 m/s | 6.5 |
| 2004 | 40.6°C | 32.6°C | 24.5°C | 45.3°C | 20.7°C | 33 mm | 28% | 2.3 m/s | 6.1 |
| 2003 | 41.3°C | 32.8°C | 24.2°C | 45.5°C | 19.7°C | 17 mm | 20% | 2.2 m/s | 6.8 |
| 2002 | 41.3°C | 32.6°C | 24.0°C | 45.0°C | 19.3°C | 5 mm | 24% | 2.2 m/s | 6.4 |
| 2001 | 40.7°C | 32.2°C | 23.6°C | 46.2°C | 19.8°C | 11 mm | 19% | 2.1 m/s | 6.6 |
| 2000 | 41.9°C | 32.5°C | 23.1°C | 44.6°C | 18.6°C | 17 mm | 19% | 2.4 m/s | 6.6 |
| 1999 | 43.2°C | 32.9°C | 22.5°C | 47.1°C | 18.6°C | 0 mm | 11% | 2.3 m/s | 7.3 |
| 1998 | 40.6°C | 31.9°C | 23.3°C | 43.7°C | 18.6°C | 6 mm | 24% | 2 m/s | 6.6 |
| 1997 | 37.9°C | 29.9°C | 21.8°C | 42.2°C | 17.3°C | 20 mm | 28% | 2.1 m/s | 6.5 |
| 1996 | 40.9°C | 32.1°C | 23.2°C | 43.3°C | 15.4°C | 9 mm | 18% | 2.1 m/s | 6.4 |
| 1995 | 41.5°C | 32.3°C | 23.2°C | 45.5°C | 17.2°C | 0 mm | 14% | 2.5 m/s | 7 |
| 1994 | 40.4°C | 31.9°C | 23.4°C | 43.2°C | 19.3°C | 11 mm | 19% | 2.2 m/s | 6.7 |
| 1993 | 40.3°C | 31.2°C | 22.1°C | 44.5°C | 16.7°C | 7 mm | 23% | 2.4 m/s | 6.5 |
| 1992 | 42.2°C | 33.1°C | 24.0°C | 44.5°C | 19.3°C | 0 mm | 16% | 3.2 m/s | 6.7 |
| 1991 | 41.1°C | 32.0°C | 22.9°C | 45.0°C | 17.6°C | 0 mm | 16% | 2.3 m/s | 6.7 |
| 1990 | 40.7°C | 31.6°C | 22.4°C | 45.6°C | 15.7°C | 2 mm | 17% | 2.9 m/s | 7 |
| 1989 | 41.6°C | 31.5°C | 21.5°C | 44.9°C | 15.5°C | 0 mm | 12% | 3.1 m/s | 7.3 |
| 1988 | 41.9°C | 32.7°C | 23.5°C | 44.8°C | 14.3°C | 13 mm | 20% | 2 m/s | 6.2 |
| 1987 | 40.8°C | 32.0°C | 23.2°C | 43.5°C | 19.7°C | 19 mm | 20% | 2.8 m/s | 6.7 |
| 1986 | 41.0°C | 32.3°C | 23.6°C | 43.7°C | 20.0°C | 22 mm | 19% | 2.2 m/s | 7.2 |
| 1985 | 41.8°C | 33.1°C | 24.4°C | 45.2°C | 21.0°C | 0 mm | 19% | 2.8 m/s | 7.1 |
| 1984 | 42.0°C | 33.5°C | 25.0°C | 44.9°C | 21.4°C | 2 mm | 17% | 2 m/s | 6.6 |
| 1983 ❄️ | 38.0°C | 29.9°C | 21.8°C | 45.2°C | 17.9°C | 10 mm | 27% | 2.7 m/s | — |
| 1982 🌧️ | 39.3°C | 30.8°C | 22.4°C | 42.3°C | 17.6°C | 59 mm | 32% | 2.3 m/s | — |
| 1981 | 39.7°C | 30.9°C | 22.0°C | 43.0°C | 16.5°C | 23 mm | 27% | 2.3 m/s | — |
Actual recorded April data for each year, 1981–2025 — sourced from NASA POWER.
The average high in April is around 40.7°C with lows near 23.5°C (mean 32.1°C), based on 45 years of NASA POWER data.
April averages 13 mm of rainfall in Siwan, one of the drier months. The wettest on record was 59 mm in 1982.
The hottest April reached 47.1°C in 1999. The coldest dipped to 14.3°C in 1988.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average April temperatures have risen by about 0.9°C. Daytime highs moved from 40.2°C to 40.9°C and overnight lows from 23.1°C to 24°C over the same span.
April is one of the warmer months of the year in Siwan and one of the drier months, so plan for around 40.7°C daytime highs and 23.5°C at night.
Not quite — April is the 10th coolest month in Siwan, averaging 32.1°C.
For April in Siwan, pack light, breathable clothing and sun protection, with typical highs of 40.7°C and lows of 23.5°C.
Relative humidity in April averages 23% — relatively dry.
Average wind speed in April is 2.4 m/s. The windiest April on record averaged 3.5 m/s (2024).
The wettest April on record was 1982 with 59 mm. On average, April sees 13 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 Siwan 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.
