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Summit Lake Reservoir — Current Water Temperature, Annual Trends and Forecast

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

Geist Reservoir, United States
Geist Reservoir, United States © By Carol M. Highsmith, Public domain

Current Water Temperature

26.8°C
Today
26.3°C
Yesterday
25.3°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 Summit Lake Reservoir today is 26.8°C.

Water Temperature: Daily Trends, Historical Records, and Forecast

✅ As of today, the minimum water temperature ranges from 79°F (26°C) to 82°F (28°C). This is very warm water, allowing for extended stays without any discomfort. Swimming in these conditions will be particularly enjoyable, making it the ideal temperature range for those who want to relax in the sea. Additionally, water in this temperature range is suitable for children and elderly people, as it is comfortable for prolonged stays. 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 June 20 to July 21

Table of Daily Sea Temperature Data

Date Current Average Forecast
JUL 1425.3°C23.8°C
JUL 1527.4°C23.8°C
JUL 1626.1°C23.8°C
JUL 1726.1°C23.8°C
JUL 1826.1°C23.8°C
JUL 1926.2°C23.8°C
JUL 2026.3°C23.8°C
JUL 2127.0°C23.8°C
JUL 2223.8°C26.7°C
JUL 2323.8°C26.5°C
JUL 2423.8°C26.4°C
JUL 2523.8°C26.2°C
JUL 2623.8°C26.1°C
JUL 2723.8°C25.9°C
JUL 2823.8°C25.8°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°C6°C9°C
February1°C6°C10°C
March2°C6°C10°C
April6°C11°C16°C
May8°C14°C20°C
June16°C23°C30°C
July20°C24°C28°C
August23°C26°C29°C
September21°C25°C29°C
October17°C20°C22°C
November4°C11°C17°C
December2°C6°C9°C

Summit Lake Reservoir: Water Temperature by Location

Summit Lake Reservoir: Weather Forecast

July 22

° / °
light drizzle
rain: 25% | wind:

July 23

° / °
overcast
rain: 0% | wind:

July 24

° / °
light drizzle
rain: 1% | wind:

July 25

° / °
light drizzle
rain: 4% | wind:

July 26

° / °
light drizzle
rain: 4% | wind:

Location & Local Information

Summit Lake Reservoir, located in Summit Lake State Park in east‑central Indiana, experiences the typical seasonal swings of Midwestern lakes. In winter the surface often approaches freezing, roughly 32–40°F (0–4°C), and may develop ice depending on air temperatures. Spring sees a steady rise as runoff and warming air bring the surface into roughly 40–60°F (4–16°C). By mid‑ to late summer the shallow, sheltered water commonly warms to about 68–82°F (20–28°C), with occasional pockets reaching the upper 80s on heat‑wave days. In autumn the temperature falls again into the 50–65°F (10–18°C) range as cooling air and shorter days reduce surface warmth. Local factors such as recent rainfall, wind, and how deep you are in the lake can shift these values by several degrees.

Swimming is generally concentrated in the park’s designated beach area and is typically permitted during the warm season when the park opens the beach and staff or lifeguards are on duty; outside those posted times swimming may be at one’s own risk or restricted. Visitors should consider water temperature and conditions—colder shoulder‑season water can cause cold‑water shock, and summer conditions can bring wind or algae that affect safety—so following park signage and guidance is advisable before entering the water.

Nearby Lakes

Frequently Asked Questions

What is the current water temperature in Summit Lake Reservoir?
Water Temperature in Summit Lake Reservoir today is 26.8°C.
What is the water temperature in Summit Lake Reservoir during the summer months?
The water temperature in Summit Lake Reservoir in summer fluctuates in the range of 16°C - 30°C.
Is it possible to swim in Summit Lake Reservoir and what are the possibilities for this?
Yes, swimming is permitted in Summit Lake Reservoir, Indiana. The lake offers a beach area for swimmers, with designated swimming zones in summer months.