Climate Insights for Costello Island, Inc Airport

The climate in Costello Island, Inc Airport is warm and mild. The average annual temperature is 20°C and approximately 736mm of precipitation falls per year. Costello Island, Inc Airport receives a notable amount of rainfall throughout the year, including during its driest month. Costello Island, Inc Airport 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, February, December, when temperatures can drop to 2°C. Light snow can occur between January and February.

Temperatures in Costello Island, Inc Airport vary considerably across the year, with a 35°C difference between the coldest and warmest months. July is the hottest month, with daytime highs reaching 37°C and an average of 31°C. January is the coolest month, with minimum temperatures around 2°C and an average of 7°C. On average, daily temperatures fluctuate by about 12°C between overnight lows and afternoon highs. The sharpest temperature change occurs between October and November, with a 7°C shift in average temperatures.

Costello Island, Inc Airport is a relatively dry area, receiving approximately 736mm of precipitation annually, which averages out to around 61mm per month. The wettest month is May, averaging 138mm of rainfall. April and October also tend to see above-average precipitation. The driest month is July, with just 31mm. That's 107mm less than May, the wettest month. Precipitation varies noticeably between seasons, with the first half (January to June) of the year generally seeing more rainfall. Light snowfall can occur between January and February, totalling around 6cm annually. February is the snowiest month with approximately 3cm.

Costello Island, Inc Airport is moderately windy, with an average annual wind speed of 21km/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 25km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in September, with average winds dropping to 17km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 8km/h gap between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 21km/h in winter, 23km/h in spring, 19km/h in summer, 19km/h in autumn.

It is currently spring in Costello Island, Inc Airport, which began on March 20, 2026. Costello Island, Inc Airport 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 37°C, while the coldest stretch bottoms out in January near 2°C. Summer is next, beginning on June 21, 2026 — 88 days from now.

The best time to visit Costello Island, Inc Airport is during March, April and October, when the weather is most comfortable for travellers. During these months, average temperatures hover around 18°C with modest rainfall averaging 77mm per month. By contrast, July can be uncomfortably hot with highs reaching 37°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 Costello Island, Inc Airport 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.