Climate and monthly weather forecastOttumwa, IA
Climate and monthly weather forecast
The climate of Ottumwa
Ottumwa, nestled in the state of Iowa in the USA, experiences a Humid continental climate, synonymous with the Köppen climate classification Dfa. This indicates the absence of a dry season, with the presence of a hot summer. Weather fluctuations across the year are significant, encapsulating a range of different meteorological conditions.Temperatures typically escalate from a chilly average low of 16.2°F (-8.8°C) in January to a summertime peak in July, with high temperatures averaging 82.6°F (28.1°C) and lows around 65.3°F (18.5°C). Whilst winters display the coldest temperatures, the end of summer brings upon the highest humidity, reaching up to 83% in June. A proportional trend between temperatures and daylight hours is evident, with more daylight correlating to warmer weather.
Rainfall is more frequent during the warmer months, reaching a peak of 4.02" (102mm) in May, gradually decreasing thereafter. Correspondingly, the number of raining days also exhibit a peak in May with 17.3 days, and a decline following that. Snowfall arises from November, peaking to 3.86" (98mm) and 10.2 snowfall days in January, depleting to none from June to September.
The average visibility remains constant throughout the year at 6 miles. In terms of both sunshine hours per day and the monthly pressure, no significant patterns emerge throughout the course of the year. However, the wind speed exhibits a mild decline from January’s 10.8mph (17.4km/h) to July’s 7mph (11.3km/h), before rising again towards the end of the year.
The best time to visit Ottumwa
Optimal visiting times for Ottumwa would feature comfortable temperatures and reduced rainfall. Given these conditions, September is most suitable. Temperatures, on average, range from lows of 56.5°F (13.6°C) to a high of 75.7°F (24.3°C), providing a pleasant climate. Rainfall and the number of raining days decrease to 2.76" (70mm) and 11.7 days, respectively. The daylight extends up to 12.5 hours, with ample sunshine of approximately 9.4 hours, ensuring an advantageous visit.The worst time to visit Ottumwa
On the contrary, January would be the least appealing month for a visit, due to harsh winter conditions. Temperatures plummet to average lows of 16.2°F (-8.8°C) with high temperatures merely reaching 29.3°F (-1.5°C). Snowfall reaches its peak, with an average of 3.86" (98mm) spread over 10.2 days. The daylight is limited to 9.6 hours with merely 4.2 hours of sunshine.Spring weather in Ottumwa
Spring in Ottumwa is marked by rising temperatures, escalating from an average low of 33.1°F (0.6°C) and high of 48.2°F (9°C) in March to 53.2°F (11.8°C) and 70°F (21.1°C) in May. Correspondingly, daylight lengthens from 12 hours in March, peaking to 14.5 hours in May. The UV index also rises from 3 to 5 between these months. Rainfall increases during the spring months, accumulating to an average high of 4.02" (102mm) in May along with an increased frequency of rainy days, reaching up to an average 17.3 days.Summer weather in Ottumwa
Summers in Ottumwa display warm temperatures, averaging between 63.1°F (17.3°C) and 82.6°F (28.1°C). The longest daylight of the year is observed in June extending up to 15.1 hours. The average rainfall is relatively high during the initial summer months, with a decrease observed later. Despite summer being the period of most prolonged daylight, it also presents the highest relative humidity, peaking at 83% in June.Autumn weather in Ottumwa
Autumn represents a transitional period in Ottumwa, with temperatures steadily decreasing from September’s average high of 75.7°F (24.3°C) to November’s average high of 47.8°F (8.8°C). Rainfall displays a slight decline from 2.76" (70mm) in September to 1.5" (38mm) by November. Daylight hours decrease from 12.5 hours in September to 9.9 hours in November and wind speed begins to rise, reaching 10.4mph (16.7km/h) in November.Winter weather in Ottumwa
Winter in Ottumwa introduces the coldest temperatures of the year, with average lows of 16.2°F (-8.8°C) in January. Snowfall is prevalent during winter, extending up to an average of 10.2 days in January. Daylight is at its shortest, with an average of 9.3 hours in December. Winters also witness significantly high relative humidity, which goes up to 79% in December.Weather in January
The New Year draws in with colder days in Ottumwa, Iowa, with snow being a common sight. January is characterized by the lowest average temperature in the year, with the highest point reaching a chilly 29.3°F (-1.5°C) and coming down to a freezing 16.2°F (-8.8°C). Weather in January »Weather in February
Moving onto February, Ottumwa sees only a slight shift in weather patterns from the preceding month. Subzero temperatures are still a common feature, but the mercury column shows a steady inclination with temperatures reaching up to 33.3°F (0.7°C). Weather in February »Weather in March
March marks a significant change as Ottumwa transitions into spring. Residents breathe a sigh of relief as the snowfall reduces to a meager 1.73" (44mm) and the prevalent cold gradually gives way to milder conditions. The hottest day can go up to 48.2°F (9°C), a notable improvement from the past months. Weather in March »Weather in April
By April, Ottumwa is in the depth of spring and the weather conditions display a clear shift from the past months. April showers become prominent, providing much-needed moisture for the emerging vegetation. A maximum temperature of 60.1°F (15.6°C) indicates the continuing upward trend, bidding goodbye to the waning winter. Weather in April »Weather in May
As the heart of Spring, May brings an increase in temperatures, lush green scenes, and chirping birds back to Ottumwa. The warmest days reach up to 70°F (21.1°C), a far cry from the freezing winter only a few months ago. Rainfall increases, promoting further growth and enhancing the city's natural beauty. Weather in May »Weather in June
June in Ottumwa marks the commencement of the much-awaited summer. It comes with long sunny days with a maximum of 15.1 hours of daylight, signifying the summer solstice. The temperature reaches up to a pleasant 79.9°F (26.6°C), alongside an increase in relative humidity. Weather in June »Weather in July
July, the peak of summer in Ottumwa, boasts the highest average temperature of the year, hitting a scorching 82.6°F (28.1°C). The town is lush with greenery, thanks to the sunlight that lasts over 14.8 hours per day. Conversely, rain showers are relatively less frequent, and the winds mild, making it perfect weather for water-based activities. Weather in July »Weather in August
August maintains the warm spell in Ottumwa with the warmest days reaching around 81.7°F (27.6°C). Compared to July, August tends to bring about slightly reduced temperatures and relative humidity. This does not take away from the joy of summer as the city continues to bask in around 13.8 daylight hours. Weather in August »Weather in September
September marks the beginning of fall in Ottumwa, with temperatures dwindling down to a maximum of 75.7°F (24.3°C). The city starts to see a reduced amount of daylight that signals the impending autumn. The atmosphere starts to become cooler and crisper, stripped of the high summer temperatures. Weather in September »Weather in October
October brings noticeable changes in Ottumwa, with foliage-rich trees turning into vibrant hues of red and orange. The temperature takes a significant dip, with the warmest day not exceeding 61.7°F (16.5°C). As the days shorten and the air turns crisper, the clear October skies often make for spectacular stargazing nights. Weather in October »Weather in November
November is the harbinger of winter in Ottumwa. After the vibrant spectacle of autumn, the town starts to prepare for the colder months ahead. The temperature dips further, with a gentle high of 47.8°F (8.8°C) setting the tone for the coming winter. Weather in November »Weather in December
The year wraps up with a full swing into winter in December. The temperature edges down to an average high of 35.1°F (1.7°C) and the city experiences an increased snowfall of about 1.57" (40mm). The Christmas season sprinkles a festive spirit over the freezing weather conditions. Weather in December »Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Ottumwa's coldest temperatures are experienced in January, with average high temperatures of 29.3°F (-1.5°C) and lows of 16.2°F (-8.8°C).
The month with the least rainfall is January, when the rain falls for 5.2 days and typically collects 1.06" (27mm) of precipitation.
Throughout the year, in Ottumwa, Iowa, there are 134.5 rainfall days, and 27.17" (690mm) of precipitation is accumulated.
January through May, October through December are months with snowfall in Ottumwa, Iowa.
Throughout the year, in Ottumwa, Iowa, there are 33.5 snowfall days, and 14.17" (360mm) of snow is accumulated.
The month with the least sunshine in Ottumwa, Iowa, is January, with an average of 4.2h of sunshine.
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.
The month with the most snowfall in Ottumwa, Iowa, is February, when snow falls for 8.3 days and typically aggregates up to 4.17" (106mm) of snow.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, 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.
May is the month with the most rainfall in Ottumwa, Iowa. Rain falls for 17.3 days and accumulates 4.02" (102mm) of precipitation.
The most humid month in Ottumwa is June, with an average relative humidity of 83%.
June through September are months without snowfall in Ottumwa, Iowa.
The month with the longest days in Ottumwa is June, with an average of 15h and 6min of daylight.
The months with the highest UV index are June through August, with an average maximum UV index of 6.
The month of July sees the average highest temperatures, reaching 82.6°F (28.1°C) at the peak and 65.3°F (18.5°C) at the low.
July has the most sunshine of the year, with an average of 10.2h of sunshine.
The least humid month in Ottumwa is October, with an average relative humidity of 72%.
The month with the shortest days is December, with an average of 9h and 18min of daylight.
Average temperature
Ottumwa, IA
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (29.3°F).
The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure
Ottumwa, IA
- Average pressure in January:
30.15"Hg - Average pressure in February:
30.13"Hg - Average pressure in March:
30.07"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
29.93"Hg - Average pressure in June:
29.89"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30.01"Hg - Average pressure in November:
30.09"Hg - Average pressure in December:
30.12"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed
Ottumwa, IA
- Average wind speed in January:
10.8mph - Average wind speed in February:
10.6mph - Average wind speed in March:
10.5mph - Average wind speed in April:
10.5mph - Average wind speed in May:
8.8mph - Average wind speed in June:
7.9mph
- Average wind speed in July:
7mph - Average wind speed in August:
6.9mph - Average wind speed in September:
7.9mph - Average wind speed in October:
9.6mph - Average wind speed in November:
10.4mph - Average wind speed in December:
10.2mph
The windiest month (with the highest average wind speed) is January (10.8mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).
Average humidity
Ottumwa, IA
The month with the highest relative humidity is June (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall
Ottumwa, IA
- Average rainfall in January:
1.06" - Average rainfall in February:
1.18" - Average rainfall in March:
2.13" - Average rainfall in April:
2.83" - Average rainfall in May:
4.02" - Average rainfall in June:
3.86"
The wettest month (with the highest rainfall) is May (4.02").
The driest month (with the least rainfall) is January (1.06").
Average rainfall days
Ottumwa, IA
- Average rainfall days in January:
5.2 days - Average rainfall days in February:
5.5 days - Average rainfall days in March:
11.8 days - Average rainfall days in April:
14 days - Average rainfall days in May:
17.3 days - Average rainfall days in June:
16.2 days
- Average rainfall days in July:
15.1 days - Average rainfall days in August:
11.8 days - Average rainfall days in September:
11.7 days - Average rainfall days in October:
10.9 days - Average rainfall days in November:
8.2 days - Average rainfall days in December:
6.8 days
The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is January (5.2 days).
Average snowfall
Ottumwa, IA
- Average snowfall in January:
3.86" - Average snowfall in February:
4.17" - Average snowfall in March:
1.73" - Average snowfall in April:
1.26" - Average snowfall in May:
0.04" - Average snowfall in June:
0"
The month with the highest snowfall is February (4.17").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Ottumwa, IA
- Average snowfall days in January:
10.2 days - Average snowfall days in February:
8.3 days - Average snowfall days in March:
4.6 days - Average snowfall days in April:
1 days - Average snowfall days in May:
0.1 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.5 days - Average snowfall days in November:
2.3 days - Average snowfall days in December:
6.5 days
The month with the highest number of snowfall days is January (10.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Ottumwa, IA
- Average daylight in January:
9h and 36min - Average daylight in February:
10h and 42min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 18min - Average daylight in May:
14h and 30min - Average daylight in June:
15h and 6min
- Average daylight in July:
14h and 48min - Average daylight in August:
13h and 48min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 6min - Average daylight in November:
9h and 54min - Average daylight in December:
9h and 18min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in January:
4h and 12min - Average sunshine in February:
4h and 30min - Average sunshine in March:
6h and 24min - Average sunshine in April:
8h and 0min - Average sunshine in May:
8h and 30min - Average sunshine in June:
9h and 48min
- Average sunshine in July:
10h and 12min - Average sunshine in August:
9h and 54min - Average sunshine in September:
9h and 24min - Average sunshine in October:
5h and 36min - Average sunshine in November:
5h and 30min - Average sunshine in December:
4h and 42min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days
Ottumwa, IA
- Average sunshine days in January:
16.5 days - Average sunshine days in February:
15.6 days - Average sunshine days in March:
14.9 days - Average sunshine days in April:
13.2 days - Average sunshine days in May:
11.6 days - Average sunshine days in June:
11.9 days
- Average sunshine days in July:
13.4 days - Average sunshine days in August:
16.7 days - Average sunshine days in September:
16.5 days - Average sunshine days in October:
18.2 days - Average sunshine days in November:
18.8 days - Average sunshine days in December:
18.9 days
The month with the most sunshine days is December (18.9 days).
The month with the least sunshine days is May (11.6 days).
Average UV index
Ottumwa, IA
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover
Ottumwa, IA
The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are August and September (Cloud cover 29).
Average visibility
Ottumwa, IA
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
