June is one of the warmer months of the year in Siwan, with average highs near 40.1°C and lows around 29.5°C (mean 34.8°C). It is a relatively wet time of year, averaging 139 mm of rainfall and 47% relative humidity across the period.
June is one of the warmer months of the year in Siwan. Across 45 years of records, the warmest June in Siwan was 2019 — when the month averaged 37.5°C — while the coldest was 2021 at 30.2°C. Typical June days reach 40.1°C with nights near 29.5°C. The long-term June temperature trend is broadly flat.
June is a relatively wet time of year in Siwan, averaging 139 mm of rainfall. The wettest June on record was 2008 with 479 mm, while the driest was 2016 at 49 mm.
Relative humidity in Siwan during June averages 47%. The most humid June was 2021 at 77%, and the least humid was 1987 at 32%.
June receives about 5.8 kWh/m²/day of solar energy in Siwan. The sunniest June was 1985 at 7 kWh/m²/day, and the cloudiest was 2021 at 4.3.
Average wind speed in Siwan during June is 2.8 m/s. The windiest June was 2023 at 3.6 m/s, while the calmest was 2014 at 1.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 35.1°C | 35.3°C | 33.6°C | 35.6°C | 34.3°C | -0.8°C |
| Avg High | 40.9°C | 40.7°C | 38.6°C | 41.0°C | 39.3°C | -1.6°C |
| Avg Low | 29.4°C | 29.9°C | 28.6°C | 30.2°C | 29.3°C | -0.1°C |
| Avg Rain | 111 mm | 126 mm | 206 mm | 106 mm | 150 mm | +39 mm |
June temperatures in Siwan have stayed relatively stable across the record.
June has ranged from a record low of 23.6°C (2013) to a record high of 48.4°C (1998).
Rainfall in June is a relatively wet time of year, averaging 139 mm, with a wettest year of 479 mm.
Daytime highs and overnight lows have shifted differently — highs fell about 0.2°C per decade while lows rose 0.1°C per decade, narrowing the gap between day and night.
A quieter season to visit Siwan
If your dates are flexible, the more temperate months of November and February tend to be the most comfortable for visiting Siwan. That said, June — with days averaging 40.1°C and nights around 29.5°C (mean 34.8°C) and higher rainfall (139 mm) — can still be rewarding for travellers who don't mind the warmth, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 39.8°C | 34.7°C | 29.6°C | 43.8°C | 25.7°C | 107 mm | 48% | 2.8 m/s | 5.3 |
| 2024 | 43.5°C | 37.4°C | 31.4°C | 48.3°C | 28.5°C | 52 mm | 37% | 2.4 m/s | 5.5 |
| 2023 | 42.9°C | 37.1°C | 31.2°C | 46.9°C | 27.4°C | 55 mm | 34% | 3.6 m/s | 6 |
| 2022 | 40.4°C | 35.0°C | 29.6°C | 45.0°C | 25.9°C | 147 mm | 45% | 2.7 m/s | 5.2 |
| 2021 ❄️ | 33.8°C | 30.2°C | 26.6°C | 39.4°C | 25.6°C | 248 mm | 77% | 2.4 m/s | 4.3 |
| 2020 | 35.2°C | 31.4°C | 27.6°C | 41.0°C | 24.8°C | 290 mm | 67% | 2.9 m/s | 4.4 |
| 2019 🔥 | 43.4°C | 37.5°C | 31.6°C | 48.0°C | 27.9°C | 58 mm | 38% | 3.2 m/s | 5.7 |
| 2018 | 41.4°C | 36.3°C | 31.2°C | 45.2°C | 28.9°C | 68 mm | 43% | 3 m/s | 5.3 |
| 2017 | 41.3°C | 35.9°C | 30.5°C | 46.2°C | 28.4°C | 67 mm | 43% | 2.5 m/s | 5.6 |
| 2016 | 40.3°C | 35.4°C | 30.6°C | 45.0°C | 26.8°C | 49 mm | 44% | 2.4 m/s | 5.9 |
| 2015 | 41.7°C | 36.1°C | 30.5°C | 47.9°C | 26.5°C | 112 mm | 39% | 2.7 m/s | 5.8 |
| 2014 | 41.9°C | 36.1°C | 30.3°C | 45.8°C | 27.7°C | 116 mm | 42% | 1.8 m/s | 5.9 |
| 2013 | 36.9°C | 32.4°C | 28.0°C | 40.7°C | 23.6°C | 182 mm | 59% | 2.7 m/s | 4.9 |
| 2012 | 43.2°C | 37.2°C | 31.2°C | 48.2°C | 28.8°C | 50 mm | 34% | 2.7 m/s | 5.7 |
| 2011 | 37.7°C | 33.0°C | 28.2°C | 43.0°C | 25.8°C | 290 mm | 57% | 3 m/s | 5.4 |
| 2010 | 41.9°C | 36.1°C | 30.3°C | 44.8°C | 27.6°C | 63 mm | 40% | 2.8 m/s | 5.9 |
| 2009 | 41.6°C | 35.3°C | 29.0°C | 44.6°C | 24.5°C | 83 mm | 38% | 2.4 m/s | 6.1 |
| 2008 🌧️ | 34.5°C | 30.9°C | 27.4°C | 41.6°C | 25.5°C | 479 mm | 71% | 2.6 m/s | 4.7 |
| 2007 | 39.7°C | 34.5°C | 29.2°C | 44.7°C | 27.2°C | 120 mm | 50% | 3.2 m/s | 5.6 |
| 2006 | 36.9°C | 32.2°C | 27.6°C | 44.2°C | 24.5°C | 188 mm | 59% | 2.1 m/s | 5.3 |
| 2005 | 43.2°C | 37.0°C | 30.9°C | 47.7°C | 27.7°C | 65 mm | 33% | 3 m/s | 6.2 |
| 2004 | 37.6°C | 32.8°C | 28.1°C | 42.5°C | 26.3°C | 210 mm | 58% | 3.4 m/s | 5.6 |
| 2003 | 40.1°C | 35.0°C | 29.8°C | 45.0°C | 27.0°C | 238 mm | 47% | 2.4 m/s | 5.2 |
| 2002 | 39.6°C | 34.2°C | 28.8°C | 43.1°C | 26.7°C | 91 mm | 49% | 2.7 m/s | 6 |
| 2001 | 36.3°C | 32.2°C | 28.2°C | 42.1°C | 26.2°C | 277 mm | 64% | 2.8 m/s | 5.4 |
| 2000 | 36.0°C | 31.7°C | 27.4°C | 41.7°C | 26.0°C | 307 mm | 67% | 2.8 m/s | 5.4 |
| 1999 | 39.8°C | 34.5°C | 29.3°C | 45.6°C | 27.3°C | 128 mm | 45% | 2.9 m/s | 5.2 |
| 1998 | 41.8°C | 36.3°C | 30.7°C | 48.4°C | 27.5°C | 58 mm | 40% | 3.2 m/s | 6.3 |
| 1997 | 41.2°C | 35.6°C | 30.0°C | 45.9°C | 25.2°C | 84 mm | 38% | 2.9 m/s | 6.2 |
| 1996 | 39.4°C | 34.4°C | 29.5°C | 46.7°C | 27.0°C | 192 mm | 48% | 2.7 m/s | 6.3 |
| 1995 | 41.9°C | 36.5°C | 31.1°C | 47.2°C | 25.7°C | 98 mm | 43% | 3.1 m/s | 5.9 |
| 1994 | 40.7°C | 35.6°C | 30.4°C | 46.7°C | 26.3°C | 96 mm | 44% | 3.2 m/s | 6.1 |
| 1993 | 41.7°C | 36.1°C | 30.4°C | 45.9°C | 26.0°C | 146 mm | 40% | 3.1 m/s | 6.5 |
| 1992 | 41.3°C | 35.0°C | 28.7°C | 45.4°C | 24.0°C | 97 mm | 40% | 2.9 m/s | 6.6 |
| 1991 | 39.2°C | 33.9°C | 28.5°C | 42.8°C | 26.0°C | 135 mm | 52% | 3.1 m/s | 5.4 |
| 1990 | 40.2°C | 35.1°C | 30.0°C | 46.4°C | 25.5°C | 228 mm | 48% | 2.7 m/s | 6.4 |
| 1989 | 40.0°C | 34.7°C | 29.5°C | 43.7°C | 27.4°C | 58 mm | 46% | 3.3 m/s | 6.5 |
| 1988 | 39.8°C | 34.4°C | 29.0°C | 44.9°C | 24.4°C | 150 mm | 48% | 2.9 m/s | 6.3 |
| 1987 | 43.9°C | 37.3°C | 30.8°C | 46.8°C | 26.3°C | 54 mm | 32% | 2.9 m/s | 6.6 |
| 1986 | 42.1°C | 36.0°C | 30.0°C | 45.9°C | 26.0°C | 84 mm | 35% | 3.1 m/s | 6.8 |
| 1985 | 42.3°C | 36.5°C | 30.7°C | 45.9°C | 27.0°C | 53 mm | 35% | 2.6 m/s | 7 |
| 1984 | 36.1°C | 31.9°C | 27.8°C | 44.8°C | 25.5°C | 270 mm | 66% | 3.2 m/s | 5.4 |
| 1983 | 42.2°C | 36.0°C | 29.8°C | 47.9°C | 27.3°C | 100 mm | 36% | 3 m/s | — |
| 1982 | 39.9°C | 34.3°C | 28.7°C | 44.7°C | 26.5°C | 153 mm | 47% | 2.2 m/s | — |
| 1981 | 41.4°C | 35.0°C | 28.6°C | 46.9°C | 24.2°C | 77 mm | 41% | 3 m/s | — |
Actual recorded June data for each year, 1981–2025 — sourced from NASA POWER.
The average high in June is around 40.1°C with lows near 29.5°C (mean 34.8°C), based on 45 years of NASA POWER data.
June averages 139 mm of rainfall in Siwan, a relatively wet time of year. The wettest on record was 479 mm in 2008.
The hottest June reached 48.4°C in 1998. The coldest dipped to 23.6°C in 2013.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average June temperatures have risen by about 0.2°C — but days and nights have moved in opposite directions. Overnight lows rose from 29.1°C to 29.7°C while daytime highs eased from 40.4°C to 40.1°C, narrowing the gap between day and night.
June is one of the warmer months of the year in Siwan and a relatively wet time of year, so plan for around 40.1°C daytime highs and 29.5°C at night.
Not quite — June is the 12th coolest month in Siwan, averaging 34.8°C.
For June in Siwan, pack light, breathable clothing and sun protection, with typical highs of 40.1°C and lows of 29.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in June averages 47% — relatively dry.
Average wind speed in June is 2.8 m/s. The windiest June on record averaged 3.6 m/s (2023).
The wettest June on record was 2008 with 479 mm. On average, June sees 139 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 June, 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 June specifically, along with year-by-year records and how the month has changed over the decades.
