Castlerock Temperature by Month
Castlerock in Londonderry County, United Kingdom sees moderate seasonal temperature shifts, with daytime highs between 9°C (48°F) in February and 17°C (63°F) in August, averaging 13°C (55°F) annually. Explore the full monthly breakdown below.
Castlerock Monthly Temperatures
Seasonal changes in Castlerock bring a little variety without extreme temperature swings. Nighttime lows range from 13°C (55°F) in August to 5°C (41°F) in February.
The chart below illustrates the average maximum day and minimum night temperatures in Castlerock by month:
Daily lows are most common between 4 AM and 6 AM. By 3 PM temperatures reach their daily high, driven by peak solar heating. August, the warmest month of the year, receives 140 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Castlerock 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.
very warm
warm
pleasant
moderate
cold
very cold
Castlerock vs World: Temperature Compared
Castlerock's average annual maximum temperature is 13°C (55°F). To put that in context, here's how it compares to a few well-known destinations:
Seville, Spain averages 23°C (73°F) a year — one of the warmer cities in Western Europe, with long hot summers.
Glasgow, Scotland averages 13°C (55°F) a year — mild but often grey, with cold winters and rarely hot summers.
San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation — summers are often cool and foggy, winters mild.
Melbourne, Australia averages 20°C (68°F) annually — known for unpredictable weather, with four seasons sometimes happening in one day.
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 Castlerock's weather — including monthly rainfall, sunshine hours, and humidity — visit our Castlerock climate page.
