Lake Berryessa — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Lake Berryessa, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Lake Berryessa today is 31.5°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature is above 82°F (28°C). This is very warm water, which may feel almost hot to most people. Swimming in such conditions is perfect for those seeking relaxation and comfort in the water. These waters are often preferred for relaxation in hot weather, as the water temperature does not cool the body significantly. However, it is important to remember that in such warm waters, caution is necessary, as prolonged exposure without rest can lead to overheating. 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
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| AUG 4 | 29.1°C | 27.4°C | |
| AUG 5 | 29.1°C | 27.4°C | |
| AUG 6 | 29.2°C | 27.4°C | |
| AUG 7 | 31.7°C | 27.4°C | |
| AUG 8 | 31.9°C | 27.4°C | |
| AUG 9 | 31.2°C | 27.4°C | |
| AUG 10 | 31.4°C | 27.4°C | |
| AUG 11 | 31.5°C | 27.4°C | |
| AUG 12 | 27.4°C | 31.3°C | |
| AUG 13 | 27.4°C | 31.1°C | |
| AUG 14 | 27.4°C | 30.9°C | |
| AUG 15 | 27.4°C | 30.7°C | |
| AUG 16 | 27.4°C | 30.5°C | |
| AUG 17 | 27.4°C | 30.3°C | |
| AUG 18 | 27.4°C | 30.1°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 |
|---|---|---|---|
| January | 7°C | 9°C | 12°C |
| February | 7°C | 10°C | 14°C |
| March | 5°C | 12°C | 19°C |
| April | 11°C | 15°C | 19°C |
| May | 16°C | 20°C | 25°C |
| June | 21°C | 24°C | 27°C |
| July | 21°C | 26°C | 31°C |
| August | 23°C | 27°C | 32°C |
| September | 21°C | 24°C | 27°C |
| October | 18°C | 22°C | 25°C |
| November | 13°C | 17°C | 20°C |
| December | 8°C | 11°C | 14°C |
Lake Berryessa: Water Temperature by Location
Lake Berryessa: Weather Forecast
August 12
August 13
August 14
August 15
Location & Local Information
Lake Berryessa’s surface temperatures vary notably through the year. In winter (December–February) the lake commonly cools to roughly 45–55°F (7–13°C). Spring (March–May) brings gradual warming, often into the mid-50s to mid-60s °F (13–18°C). Peak warmth occurs in summer (June–August) when surface readings typically reach about 68–78°F (20–26°C), though shallow, sunlit bays can get a few degrees warmer on hot days. In autumn (September–November) temperatures generally fall back into the 60s to low 70s °F (15–22°C) range as air temperatures decline. Deeper water remains colder year-round, so conditions can change quickly with depth and location.
Swimming is allowed in many parts of Lake Berryessa because the reservoir is managed for multiple recreational uses, including bathing and boating, but it is subject to local rules and seasonal advisories. Many shorelines and recreation areas permit swimming, yet lifeguards are uncommon and some zones—near the dam, in marina channels, or during water-quality or algal-bloom advisories—are restricted for safety. Cold-water shock, sudden depth changes, submerged hazards, and occasional water-quality issues mean swimmers should check current conditions, wear flotation if uncertain, and exercise caution even when surface temperatures feel comfortable.