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Runcorn — Current Water Temperature, Annual Trends and Forecast

This page provides information on the current water temperature in Runcorn, trends, monthly ranges and the forecast for the coming days.

Runcorn, United Kingdom
Runcorn, United Kingdom © By Geoff Wynne, CC BY-SA 2.0

Current Water Temperature

18.4°C
Today
18.3°C
Yesterday
16.7°C
A Week Ago
Get instant access to real-time water temperatures for this and all other locations with our iOS and Android apps.

Water Temperature in Runcorn today is 18.4°C.

Water Temperature: Daily Trends, Historical Records, and Forecast

⚠️ As of today, the minimum water temperature ranges from 65°F (18°C) to 68°F (20°C). This is already quite warm water, which is ideal for most people. Swimming becomes comfortable, and prolonged stays in the water do not cause discomfort. This temperature is perfect for family trips and for those who prefer warmer water. It is also comfortable for water sports such as surfing or swimming. It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.

Water Temperature Chart Over the Last 30 Days

From May 31 to July 1

Table of Daily Sea Temperature Data

Date Current Average Forecast
JUN 2416.7°C18.0°C
JUN 2516.7°C18.0°C
JUN 2616.7°C18.0°C
JUN 2718.4°C18.0°C
JUN 2818.5°C18.0°C
JUN 2917.9°C18.0°C
JUN 3018.3°C18.0°C
JUL 118.4°C19.0°C
JUL 219.0°C18.4°C
JUL 319.0°C18.5°C
JUL 419.0°C18.5°C
JUL 519.0°C18.5°C
JUL 619.0°C18.6°C
JUL 719.0°C18.6°C
JUL 819.0°C18.6°C

* Current - Actual water temperature value

** Average - Average water temperature on this day in recent years

*** Forecast - Our water temperature forecast

Actual nearshore water temperatures may fluctuate by several degrees from the reported values, especially following heavy rainfall or extended periods of strong winds. Certain wind patterns can cause colder, deeper waters to rise and replace the sun-warmed surface water, leading to noticeable variations.

Our forecast is based on a proprietary mathematical model that considers real-time water temperature changes, historical trends, key weather patterns, wind strength and direction, and air temperature specific to each region. Additionally, we incorporate data from other resorts to enhance accuracy.

Monthly Water Temperature Range (Min, Max & Average)

Month Min Avg Max
January1°C5°C8°C
February1°C5°C8°C
March2°C6°C9°C
April6°C9°C12°C
May9°C14°C18°C
June14°C18°C23°C
July15°C19°C24°C
August14°C18°C23°C
September11°C16°C20°C
October9°C12°C15°C
November4°C7°C10°C
December1°C5°C8°C

Runcorn: Weather Forecast

July 2

° / °
moderate drizzle
rain: 82% | wind:

July 3

° / °
overcast
rain: 11% | wind:

July 4

° / °
light drizzle
rain: 27% | wind:

July 5

° / °
overcast
rain: 21% | wind:

July 6

° / °
overcast
rain: 8% | wind:

Location & Local Information

Runcorn, a town in Cheshire, sits on the upper tidal reach of the River Mersey, where the river begins to widen toward its estuary near Liverpool. The water here reflects the region’s maritime climate, influenced by both inland flow and tidal mixing. In winter, the Mersey around Runcorn typically measures between 5 and 7°C (41–45°F), remaining cold and fast-moving. By spring, it gradually warms to about 9–11°C (48–52°F). During midsummer—particularly in July and August—the water can reach 16–18°C (61–64°F) in calm conditions, though tidal changes often make it feel cooler. As autumn arrives, the river cools again to around 10–12°C (50–54°F), maintaining a steady freshness throughout much of the year.

Swimming in the River Mersey near Runcorn is possible but generally not advised due to strong tides, variable depths, and limited visibility. The tidal flow can shift rapidly, and industrial activity along parts of the river adds further challenges. Wild swimming is safer in nearby lakes or controlled open-water venues. For those who prefer to stay by the shore, the Mersey offers pleasant walking and cycling routes with views of the Silver Jubilee Bridge. Nearby attractions include Norton Priory Museum, Runcorn Hill Park, and access to the wider Mersey Valley Trail.

Nearby Locations

Frequently Asked Questions

What is the current water temperature in Runcorn?
Water Temperature in Runcorn today is 18.4°C.
What is the water temperature in Runcorn during the summer months?
The water temperature in Runcorn in summer fluctuates in the range of 14°C - 24°C.
Is it possible to swim in Runcorn (United Kingdom) in River Mersey and what are the possibilities for this?
You can swim in the River Mersey at Runcorn, but there are no designated bathing areas and the estuary’s strong tides, currents and variable urban/industrial discharges make unsupervised wild swimming risky, so the safer options are to check local water-quality and access rules and either join organised, supervised open‑water swims or local clubs that use sheltered stretches with safety measures, or use public pools and lidos.