John Martin Reservoir — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in John Martin Reservoir, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in John Martin Reservoir today is 22.3°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature ranges from 68°F (20°C) to 74°F (23°C). The water is warm and pleasant for swimming, and in this range, one can stay in the water for extended periods without the risk of hypothermia. This is the ideal temperature for relaxation, swimming, and water sports. Families with children, as well as outdoor enthusiasts, will enjoy swimming and time spent in the water. For most people, this is the optimal temperature for a comfortable beach experience. 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 |
|---|---|---|---|
| JUN 6 | 20.4°C | 20.2°C | |
| JUN 7 | 22.1°C | 20.2°C | |
| JUN 8 | 22.5°C | 20.2°C | |
| JUN 10 | 23.3°C | 20.2°C | |
| JUN 11 | 23.4°C | 20.2°C | |
| JUN 12 | 22.4°C | 20.2°C | |
| JUN 13 | 22.3°C | 20.2°C | |
| JUN 14 | 20.2°C | 22.2°C | |
| JUN 15 | 20.2°C | 22.1°C | |
| JUN 16 | 20.2°C | 22.0°C | |
| JUN 17 | 20.2°C | 21.9°C | |
| JUN 18 | 20.2°C | 21.8°C | |
| JUN 19 | 20.2°C | 21.7°C | |
| JUN 20 | 20.2°C | 21.6°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 | 1°C | 4°C | 8°C |
| February | 1°C | 5°C | 9°C |
| March | 1°C | 8°C | 15°C |
| April | 9°C | 14°C | 19°C |
| May | 14°C | 17°C | 21°C |
| June | 17°C | 20°C | 24°C |
| July | 21°C | 23°C | 26°C |
| August | 22°C | 24°C | 27°C |
| September | 19°C | 21°C | 24°C |
| October | 13°C | 17°C | 21°C |
| November | 7°C | 11°C | 14°C |
| December | 3°C | 6°C | 9°C |
John Martin Reservoir: Water Temperature by Location
John Martin Reservoir: Weather Forecast
June 14
June 15
June 16
June 17
Location & Local Information
John Martin Reservoir, a large impoundment on the Arkansas River in southeastern Colorado, experiences a wide range of surface water temperatures over the year. In winter the surface often chills to near freezing, roughly 32–45°F (0–7°C). Spring brings steady warming with typical surface temperatures in the range of 45–65°F (7–18°C) as runoff and air temperatures rise. In summer the reservoir is most comfortable for water contact, with surface temperatures commonly around 70–80°F (21–27°C) and occasionally reaching the mid‑80s (about 29°C) on very hot days. During autumn the water cools again, generally falling into the 50–70°F (10–21°C) band as air temperatures drop.
Swimming is permitted at John Martin Reservoir as part of its recreational uses, but it is managed on a swim‑at‑your‑own‑risk basis rather than with staffed lifeguards. Conditions that influence safety include sudden temperature changes, chilly subsurface layers, strong winds and wake from boats, and occasional water‑quality issues such as turbidity or algal concentrations, so responsible precautions are recommended. Visitors should use designated access points, be mindful of boating traffic, and check current park advisories before entering the water.