Upper Klamath Lake — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in Upper Klamath Lake, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in Upper Klamath Lake today is 19.9°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
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| SEP 14 | 20.6°C | 19.0°C | |
| SEP 15 | 20.4°C | 19.0°C | |
| SEP 16 | 19.8°C | 19.0°C | |
| SEP 17 | 20.5°C | 19.0°C | |
| SEP 18 | 20.4°C | 19.0°C | |
| SEP 19 | 20.3°C | 19.0°C | |
| SEP 20 | 20.4°C | 19.0°C | |
| SEP 21 | 19.9°C | 19.0°C | |
| SEP 22 | 19.0°C | 19.9°C | |
| SEP 23 | 19.0°C | 19.8°C | |
| SEP 24 | 19.0°C | 19.8°C | |
| SEP 25 | 19.0°C | 19.7°C | |
| SEP 26 | 19.0°C | 19.7°C | |
| SEP 27 | 19.0°C | 19.6°C | |
| SEP 28 | 19.0°C | 19.6°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 |
|---|---|---|---|
| January | 0°C | 2°C | 4°C |
| February | 0°C | 2°C | 4°C |
| March | 1°C | 7°C | 12°C |
| April | 7°C | 11°C | 15°C |
| May | 11°C | 16°C | 21°C |
| June | 14°C | 19°C | 23°C |
| July | 18°C | 22°C | 26°C |
| August | 17°C | 22°C | 27°C |
| September | 16°C | 19°C | 22°C |
| October | 9°C | 13°C | 16°C |
| November | 2°C | 6°C | 9°C |
| December | 0°C | 3°C | 5°C |
Upper Klamath Lake: Water Temperature by Location
Upper Klamath Lake: Weather Forecast
September 22
September 23
September 24
September 25
September 26
Location & Local Information
Upper Klamath Lake, a broad, shallow inland lake in southern Oregon, experiences a wide range of surface temperatures through the year. In winter the water commonly sits in the mid-30s to low-40s °F (about 1–6 °C). Spring sees a gradual rise into the 40s and 50s °F (4–15 °C) as air temperatures warm and runoff declines. By summer, surface temperatures often reach the mid-60s to low-70s °F (roughly 18–24 °C) on warm, sunny days, though localized shallows can warm a little more while deeper or wind-swept areas remain cooler. In autumn the lake cools back into the 50s and 40s °F (10–7 °C) as nights lengthen and weather turns cooler.
Swimming at Upper Klamath Lake is generally permitted from a legal standpoint and many people recreate there, but conditions vary and caution is advised. The lake’s shallow profile and nutrient-rich waters make it prone to algal blooms—including blue‑green (cyanobacterial) blooms—that can produce toxins, so public health advisories sometimes recommend avoiding contact. Water clarity, vegetation, and cold temperatures outside of peak summer also limit comfortable swimming. Anyone planning to swim should check local advisories, avoid discolored or scummy water, and be prepared for cooler-than-expected temperatures away from the warmest surface patches.