Guernsey Temperature by Month
Guernsey in Guernsey island, United Kingdom sees moderate seasonal temperature shifts, with daytime highs between 11°C (52°F) in February and 19°C (66°F) in August, averaging 14°C (57°F) annually. Explore the full monthly breakdown below.
Guernsey Monthly Temperatures
Seasonal changes in Guernsey bring a little variety without extreme temperature swings. Nighttime lows range from 16°C (61°F) in August to 7°C (45°F) in February.
The chart below illustrates the average maximum day and minimum night temperatures in Guernsey by month:
The coldest point of the day usually falls between 4 AM and 6 AM, with temperatures peaking around 3 PM. August, the city's warmest month, gets 232 hours of sunshine.
The chart below shows the average temperature throughout the year:
Daily Historical Temperatures
50-year average (1976-2025)
Average high and low temperatures for each day of the month based on long-term records.
Average temperatures in June
Historical Guernsey Temperatures: 1976-2026
Browse day-by-day temperature records for Guernsey spanning 51 years. Select any month and year to see actual high and low temperatures recorded on each day.
Temperature: Guernsey vs the United Kingdom
The map below shows the annual temperature across the United Kingdom. You can also select individual months if you want to compare a specific time of year.
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Guernsey vs World: Temperature Compared
Guernsey's average annual maximum temperature is 14°C (57°F). To put that in context, here's how it compares to a few well-known destinations:
Barcelona, Spain has an annual average of around 21°C (70°F), with warm summers and mild, fairly short winters.
On the cooler end, Oslo, Norway averages just 10°C (50°F) annually, with pleasant summers but long, cold winters.
San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation — summers are often cool and foggy, winters mild.
Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained — so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.
For more on Guernsey's weather — including monthly rainfall, sunshine hours, and humidity — visit our Guernsey climate page.
