Blenheim has a temperate climate with warm summers and cold winters.
Temperatures peak in February and drop to their lowest in July, while rainfall is highest during summer months.
Humidity remains high throughout the year creating cold and damp conditions.
| Month | 🌤️ | Avg High | Avg Temp | Avg Low | Record High | Record Low | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|---|---|
| January | ☀️ | 21.7°C | 16.4°C | 11.1°C | 32.2°C | 4.0°C | 71% | 59 | 2.4 | 6.62 |
| February | ☀️ | 21.8°C | 16.5°C | 11.3°C | 32.2°C | 3.3°C | 72% | 57 | 2.3 | 5.79 |
| March | 🌤️ | 19.5°C | 14.6°C | 9.8°C | 28.2°C | 2.5°C | 76% | 63 | 2.2 | 4.59 |
| April | 🌤️ | 16.2°C | 11.9°C | 7.6°C | 23.8°C | 0.3°C | 82% | 70 | 2.1 | 3.15 |
| May | ☔ | 12.9°C | 9.3°C | 5.6°C | 19.9°C | -1.0°C | 87% | 80 | 2.1 | 2.16 |
| June | ☔ | 10.0°C | 6.9°C | 3.7°C | 16.9°C | -2.0°C | 90% | 91 | 2.1 | 1.61 |
| July | ☔ | 9.2°C | 6.1°C | 2.9°C | 14.3°C | -2.5°C | 90% | 89 | 2.1 | 1.84 |
| August | 🌨️ | 10.3°C | 6.8°C | 3.4°C | 16.6°C | -2.6°C | 88% | 76 | 2.1 | 2.67 |
| September | 🌨️ | 12.3°C | 8.4°C | 4.4°C | 19.1°C | -1.5°C | 85% | 69 | 2.4 | 3.81 |
| October | 🌤️ | 14.4°C | 10.1°C | 5.8°C | 22.7°C | -0.6°C | 82% | 72 | 2.5 | 5.05 |
| November | 🌤️ | 16.6°C | 12.1°C | 7.5°C | 25.2°C | 0.7°C | 79% | 63 | 2.5 | 6.09 |
| December | 🌤️ | 19.1°C | 14.4°C | 9.7°C | 28.6°C | 2.3°C | 76% | 72 | 2.5 | 6.41 |
Showing average climate conditions across 45 years (1981–2025)
🧥 Expect frosty nights and below-freezing temperatures during this Cold Winter period.
🌤️ Conditions are ideal for outdoor activities throughout the day in this Mild Summer.
☔ Moderate Rainfall expected — carry rain gear and plan outdoor activities around these months.
Monthly averages · 1981–2025 climate normals · °C
Temperatures rise steadily from spring, peak in February, and gradually decline through autumn into winter.
These seasonal patterns make summer pleasant for travel, while winters can bring frost and occasional snowfall.
Monthly rainfall · 1981–2025 seasonal trends · mm/month
Rainfall is concentrated in the summer months. Humidity stays high (around 82%), peaking during summer months, which creates cold and damp conditions.
☔ Moderate Rainfall expected — carry rain gear and plan outdoor activities around these months.
Monthly averages · 1981–2025
Across 45 years of records, Blenheim's temperature has remained relatively stable over the past decade. Its hottest day reached 32.2°C in February 2009, and its coldest dropped to -2.6°C in August 2016. 1998 was the warmest year overall and 1992 the coolest.
The warmest year in Blenheim's recorded history was 1998 (avg: 11.9°C), while the coldest was 1992 (avg: 9.6°C).
Average annual high/low · Last 30 years · °C
Total annual precipitation · Last 30 years · mm/year
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|---|---|
2025 | 15.6°C | 11.5°C | 7.4°C | 27.2°C | -1.5°C | 1127 | 84% | 2.2 m/s |
2024 | 15.8°C | 11.5°C | 7.2°C | 28.6°C | -1.1°C | 859 | 82% | 2.2 m/s |
2023 | 15.3°C | 11.5°C | 7.7°C | 25.8°C | -0.7°C | 1033 | 85% | 2.2 m/s |
2022 | 15.1°C | 11.4°C | 7.8°C | 25.8°C | -1.2°C | 1284 | 86% | 2.3 m/s |
2021 | 15.5°C | 11.5°C | 7.4°C | 31.1°C | -2.5°C | 1040 | 84% | 2.3 m/s |
2020 | 15.7°C | 11.5°C | 7.3°C | 30.1°C | -0.2°C | 839 | 82% | 2.3 m/s |
2019 | 16.0°C | 11.7°C | 7.4°C | 31.8°C | -0.8°C | 949 | 82% | 2.3 m/s |
2018 | 15.2°C | 11.4°C | 7.6°C | 28.5°C | 0.1°C | 1238 | 86% | 2.2 m/s |
2017 | 15.3°C | 11.3°C | 7.3°C | 26.5°C | -1.0°C | 1014 | 84% | 2.2 m/s |
2016 | 15.7°C | 11.6°C | 7.4°C | 29.3°C | -2.6°C | 1040 | 83% | 2.3 m/s |
Showing 1 to 10 of 45 years
No cities found.
Based on 45 years of data (1981–2025), February is typically the hottest month in Blenheim, Marlborough, with average high temperatures around 21.8°C.
July is the coldest month in Blenheim, with average low temperatures around 2.9°C.
June receives the most rainfall with approximately 91 mm, while February is the driest with 57 mm.
The highest recorded temperature was 32.2°C in February 2009. This is part of the historical record spanning 1981–2025.
The lowest recorded temperature was -2.6°C in August 2016.
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
Blenheim receives the most sunlight in January with an average solar radiation of 6.62 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning and agriculture in Marlborough.
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.
