Climate Overview
The climate in Port Glasgow is cool. The average annual temperature is 9°C and approximately 1713mm of precipitation falls per year. Port Glasgow receives a notable amount of rainfall throughout the year, including during its driest month. Port Glasgow is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, June, July. The coldest months are February, November, January, when temperatures can drop to 1°C. Snowfall occurs from January to December, with around 109cm accumulating over the season.
Temperature
Port Glasgow sees moderate temperature variation throughout the year, ranging from 1°C to 17°C. August is the warmest month, though highs remain moderate at 17°C with a mean of 14°C. February is the coolest month, with minimum temperatures around 1°C and an average of 3°C. Daily temperature variation is modest, with an average difference of 5°C between highs and lows. The sharpest temperature change occurs between October and November, with a 5°C shift in average temperatures.
Precipitation
Port Glasgow is a fairly wet location, receiving approximately 1713mm of precipitation annually, which averages out to around 143mm per month. The wettest month is January, averaging 250mm of rainfall. September and February also tend to see above-average precipitation. The driest month is October, with just 54mm. That's 197mm less than January, the wettest month. Precipitation varies noticeably between seasons, with the first half (January to June) of the year generally seeing more rainfall. Snowfall is a regular feature from January to December, with around 109cm accumulating over the season. January typically sees the most snow at around 50cm.
Wind
Port Glasgow 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 December, averaging 4km/h, though still comfortable for most outdoor activities. The calmest conditions occur in June, with average winds dropping to 3km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 1km/h gap between the calmest and windiest months.
Seasons
52 days until Autumn
It is currently summer in Port Glasgow, which began on June 21, 2026. Port Glasgow 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 August at around 17°C, while the coldest stretch bottoms out in February near 1°C. Autumn is next, beginning on September 23, 2026 — 52 days from now.
Spring
Temperatures range from 2 to 15°C. Rainfall is heavy, totalling around 337mm across the season with a monthly average of 112mm. Winds are generally light, averaging 3km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 10 to 17°C. Rainfall is heavy, totalling around 412mm across the season with a monthly average of 137mm. Winds are generally light, averaging 3km/h. Comfortable clothing with a light layer for cooler evenings is all you need.
Autumn
Temperatures range from 1 to 16°C. Rainfall is heavy, totalling around 391mm across the season with a monthly average of 130mm. Expect around 13cm of snow accumulation during this period. Winds are generally light, averaging 4km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 1 to 9°C. Rainfall is heavy, totalling around 573mm across the season with a monthly average of 191mm. Expect around 75cm of snow accumulation during this period. Winds are generally light, averaging 4km/h. Warm winter clothing and waterproof boots are a must, and travel may be affected by snow.
Monthly Climate Data
The table below shows monthly climate averages for Port Glasgow 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.
