Climate and monthly weather forecast
Waterloo, IA

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The climate of Waterloo

Waterloo is a city situated in northeastern Iowa. Its weather is governed by its geographical position and falls under the Dfa category of the Köppen climate classification, denoting humid continental conditions with no dry season and hot summers. This classification translates into varying weather conditions throughout the year, with significant changes across seasons in the key climatic parameters.

Looking at the temperatures, the warmest month in Waterloo generally is July, when highs reach an average of 80.1°F (26.7°C), while the lowest temperatures are seen in January with an average low of 12°F (-11.1°C). The city witnesses seasonal fluctuations in humidity too, with the most humid month being January (87% relative humidity) and the least humid being April (73% relative humidity).

Apart from temperature and humidity, precipitation is another vital weather element in this region. Highest average rainfall occurs in May and June with 4.21in and 4.29in respectively. Conversely, least rainfall can be noticed in January and February with an average of 1.02in. June seems to hold the supremacy in terms of rainfall days, recording approximately 18.1 days of rainfall uptick.

It is important to note that Waterloo also gets its share of snowfall. Snowfall typically occurs from late October through early April, with the most snowfall recorded in January (4.21in) and December comes second (2.8in).

The best time to visit Waterloo

Considering the various weather parameters, the best time to visit Waterloo would ideally be between May and September. This period marks the warm season with pleasant temperatures ranging from 56.8°F (13.8°C) to 78.6°F (25.9°C). The rainfall during this period is scattered and usually does not disrupt outdoor activities. Furthermore, the city basks in the sunlight for approximately 9.5h to 9.7h per day, making it perfect for sightseeing and other outdoor pursuits.

The worst time to visit Waterloo

The months from December to February could be construed as the worst time to visit Waterloo. During this period, the city experiences its coldest weather with average low temperatures dropping down to 12°F (-11.1°C) and maximums barely reaching 28.4°F (-2°C). Besides, significant snowfall occurs during these months, recording up to 4.21in in January. Traveling conditions could be hindered due to heavy snow and icy roads.

Spring weather in Waterloo

Spring in Waterloo is characterized by a slow yet steady rise in temperatures. During this season, average highs range from 44.1°F (6.7°C) in March to 68.2°F (20.1°C) in May, while lows migrate from a chilly 29.7°F (-1.3°C) to a more comfortable 51.6°F (10.9°C) in the same period. March and April bring moderate rainfall with an average of 1.73in and 3.19in respectively, while May witnesses the peak with 4.21in.

Summer weather in Waterloo

Summers in Waterloo, encompassing June through August, are typically warm and humid. The mercury hovers between an average high of 77.7°F (25.4°C) in June and 78.6°F (25.9°C) in August. Minimum temperatures during this season are quite pleasant, fluctuating between 61.3°F (16.3°C) to 63.1°F (17.3°C). Despite the high temperatures, the city has an ample amount of rain with June being the wettest month (4.29in) of the year.

Autumn weather in Waterloo

Autumn in Waterloo brings a significant drop in temperatures, particularly between September and November. Maximum temperatures drop from 73.2°F (22.9°C) in September to 44.1°F (6.7°C) in November, while average lows plunge from 54.5°F (12.5°C) to a chilly 31.1°F (-0.5°C) in the same period. This season also sees a moderate decrease in rainfall with November being the driest (1.54in).

Winter weather in Waterloo

Winter in Waterloo is characterized by cold temperatures and snowfall. December to February sees average highs range from 31.1°F (-0.5°C) to 24.3°F (-4.3°C) while the corresponding lows grapple between 20.5°F (-6.4°C) to 12°F (-11.1°C). Both January and February host a substantial average snowfall of 4.21in and 4.17in respectively, contributing to challenging road conditions and providing scenic white landscapes.

Weather in January

Iowa residents all know that January in Waterloo is defined by snowfall and cold temperatures. Snow blankets the city while the wind blows the white, icy powder around. This month experiences the coldest temperatures, with the high barely reaching 24.3°F (-4.3°C) and the low plummeting to 12°F (-11.1°C). Weather in January »

Weather in February

February brings slightly warmer temperatures to Waterloo. While it is still the height of winter, the worst of the year's cold is typically in the rearview mirror. Although snowfall and cold temperatures persist, they are less intense compared to the previous month. Weather in February »

Weather in March

As winter fades and spring emerges, March experiences a noticeable increase in temperature, presenting more opportunity for outdoor activities. The city beholds a significant reduction in snowfall and an increase in rainfall, indicating the commencement of the spring melting period. Weather in March »

Weather in April

By the time April arrives in Waterloo, the city is under the full influence of spring. Flowering trees and shrubs are welcoming additional sunlight and warmer temperatures each day. Rainfall is more frequent in April than in the previous month, which contributes to the vibrancy of awakening plant life. Weather in April »

Weather in May

In May, Waterloo leaves behind the freshness of the spring season and transitions into the first hints of summer warmth. A significant increase in the average high and low temperatures means that residents spend more time outdoors. Weather in May »

Weather in June

Waterloo experiences mild and pleasant weather through much of June. The shift into summer is unmistakable as abundant sunshine graces the city. The skyline is typically clear, with cloud coverage at its lowest of the year. While high temperatures average a comfortable 77.7°F (25.4°C), the amount of relative humidity begins to rise, paving the way for sultry summer days ahead. Weather in June »

Weather in July

July in Waterloo is defined by the peak of summer with the warmest weather of the year. The temperature routinely rises above average with high temperatures reaching an average of 80.1°F (26.7°C). The citizens of Waterloo can spend their days enjoying various outdoor activities due to lengthy daylight hours, despite the relatively high humidity. Weather in July »

Weather in August

August sees the continuation of summery weather patterns in Waterloo- warm temperatures, long days, and abundance of sunshine. Nevertheless, compared to July, there's a slight decrease in temperature, offering relief to residents. Weather in August »

Weather in September

With the end of summer, September in Waterloo comes with more moderate temperatures and the first hints of fall. An unmistakable onset of the autumn season is experienced this month as the landscape begins to transform. The average high temperature drops to 73.2°F (22.9°C), a noticeable decrease from August. Weather in September »

Weather in October

October in Waterloo signals the full arrival of fall with a clear drop in temperature and the foliage's vibrant colors. The city witnesses a surge in wind speed, averaging 9.8mph (15.8km/h) along with a reduction in average high temperatures which dip to 58.5°F (14.7°C). Weather in October »

Weather in November

November in Waterloo introduces the upcoming winter with a sharp decline in temperature. Despite the cold, clear days with vibrant sunshine are quite usual. The first snowflakes may start to appear, setting the stage for the winter wonderland that ensues. Weather in November »

Weather in December

As the year wraps up, December in Waterloo is characterized by winter's full onset, with snowfall and chilly temperatures being the norm. The holidays bring a magical touch to the snow-covered city, enhancing its charm. The lowest high temperatures of the year occur in December, with an average high of 31.1°F (-0.5°C). Weather in December »
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the coldest in Waterloo?

With average temperatures fluctuating between a high of 24.3°F (-4.3°C) and a low of 12°F (-11.1°C), January stands out as the coldest month.

What is the most humid month in Waterloo?

The most humid month is January, with an average relative humidity of 87%.

What is the driest month in Waterloo?

The months with the least rainfall in Waterloo, Iowa, are January and February Rain falls for 4.1 days and accumulates 1.02" (26mm) of rain.

How much does it rain in Waterloo?

Throughout the year, in Waterloo, there are 133.6 rainfall days, and 28.27" (718mm) of precipitation is accumulated.

When does it snow in Waterloo?

Months with snowfall are January through May, October through December.

When does it snow the most in Waterloo?

The month with the most snowfall is January, when snow falls for 11.5 days and typically aggregates up to 4.21" (107mm) of snow.

How many days does it snow in Waterloo?

Throughout the year, there are 41.6 snowfall days, and 15.24" (387mm) of snow is accumulated.

What is the month with the least sunshine in Waterloo?

With an average of 3.8h of sunshine, January has the least sunshine of the year.

When is Daylight Saving Time (DST) in Waterloo?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Waterloo, Iowa, and the time zone changes from CST to CDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from CDT to CST.

What is the rainiest month in Waterloo?

The month with the most rainfall in Waterloo is June, when the rain falls for 18.1 days and typically aggregates up to 4.29" (109mm) of precipitation.

When it does not snow in Waterloo?

June through September are months without snowfall in Waterloo.

When are the longest days in Waterloo?

June has the longest days of the year in Waterloo, with an average of 15h and 12min of daylight.

What is the month with the highest UV index in Waterloo?

With an average maximum UV index of 6, June is the month with the highest UV index in Waterloo, Iowa.

What time of the year is the hottest in Waterloo?

July is the warmest month in Waterloo, Iowa, exhibiting average temperatures of 80.1°F (26.7°C) at the peak and 63.1°F (17.3°C) at the base.

What month has the most sunshine in Waterloo?

With an average of 9.9h of sunshine, July has the most sunshine of the year.

What is the least humid month in Waterloo?

October is the least humid month in Waterloo, with an average relative humidity of 72%.

What is the month with the shortest days in Waterloo?

December has the shortest days of the year in Waterloo, with an average of 9h and 6min of daylight.

When is the lowest UV index in Waterloo?

With an average maximum UV index of 1, December is the month with the lowest UV index in Waterloo.

Average temperature
Waterloo, IA

Average temperature - Waterloo, IA

The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (24.3°F).

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (12°F).

Average pressure
Waterloo, IA

Average pressure - Waterloo, IA

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed
Waterloo, IA

Average wind speed - Waterloo, IA

The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest month (with the lowest average wind speed) is August (7mph).

Average humidity
Waterloo, IA

Average humidity - Waterloo, IA

The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (72%).

Average rainfall
Waterloo, IA

Average rainfall - Waterloo, IA

The wettest month (with the highest rainfall) is June (4.29").
The driest months (with the least rainfall) are January and February (1.02").

Average rainfall days
Waterloo, IA

Average rainfall days - Waterloo, IA

The month with the highest number of rainy days is June (18.1 days).
The month with the least rainy days is February (4 days).

Average snowfall
Waterloo, IA

Average snowfall - Waterloo, IA

The month with the highest snowfall is January (4.21").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days
Waterloo, IA

Average snowfall days - Waterloo, IA

The month with the highest number of snowfall days is January (11.5 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight / Average sunshine
Waterloo, IA

Average daylight / Average sunshine - Waterloo, IA

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).

The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

Average sunshine days
Waterloo, IA

Average sunshine days - Waterloo, IA

The month with the most sunshine days is October (17.8 days).
The month with the least sunshine days is June (10 days).

Average visibility
Waterloo, IA

Average visibility - Waterloo, IA

The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).

Waterloo, Iowa, USA

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