Climate Insights for Hennessey

The climate in Hennessey is temperate. The average annual temperature is 16°C and approximately 839mm of precipitation falls per year. May is the wettest month, receiving around 150mm of rainfall. Hennessey is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, June. The coldest months are January, December, February, when temperatures can drop to -2°C. Light snow can occur between January and December.

Hennessey has a wide annual temperature range, spanning 37°C from the coldest to warmest months. July is the hottest month, with daytime highs reaching 35°C and an average of 29°C. The coldest month is January, when overnight lows fall to -2°C and the daily average is 3°C. On average, daily temperatures fluctuate by about 12°C between overnight lows and afternoon highs. The sharpest temperature change occurs between September and October, with a 8°C shift in average temperatures.

Hennessey is a moderately rainy area, receiving approximately 839mm of precipitation annually, which averages out to around 70mm per month. The wettest month is May, averaging 150mm of rainfall. April and September also tend to see above-average precipitation. The driest month is November, with just 24mm. That's 126mm less than May, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic. Light snowfall can occur between January and December, totalling around 15cm annually. January is the snowiest month with approximately 6cm.

Hennessey is relatively calm, with an average annual wind speed of 4km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is April, averaging 5km/h, though still comfortable for most outdoor activities. The calmest conditions occur in August, with average winds dropping to 3km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 2km/h between the calmest and windiest months.

It is currently spring in Hennessey, which began on March 20, 2026. Hennessey is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 35°C, while the coldest stretch bottoms out in January near -2°C. Summer is next, beginning on June 21, 2026 — 3 days from now.

The best time to visit Hennessey is during September and October, when the weather is most comfortable for travellers. During these months, average temperatures hover around 20°C with modest rainfall averaging 85mm per month. By contrast, July can be uncomfortably hot with highs reaching 35°C, while January is the coldest period with lows dropping to -2°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for Hennessey based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.