October weather forecast
Grinnell, IA

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Weather in October

October, like September, is a moderate autumn month in Grinnell, Iowa, with an average temperature varying between 44.4°F (6.9°C) and 59.9°F (15.5°C).

Temperature

With the transition into October, Grinnell experiences a significant decrease in average high-temperatures, moving down from a moderately hot 74.7°F (23.7°C) in September to a mild 59.9°F (15.5°C). An average low-temperature of 44.4°F (6.9°C) marks the month of October in Grinnell.

Humidity

October is the least humid month, with an average relative humidity of 71%.

Rainfall

In Grinnell, in October, during 9.1 rainfall days, 0.94" (24mm) of precipitation is typically accumulated. Throughout the year, there are 117.5 rainfall days, and 13.03" (331mm) of precipitation is accumulated.

Snowfall

January through May, October through December are months with snowfall in Grinnell. October is the first month it typically snows. Throughout October, in the average 0.5 snowfall days, it receives 0.31" (8mm) of snow. Throughout the year, there are 30.7 snowfall days, and 6.06" (154mm) of snow is accumulated.

Daylight

The average length of the day in October is 11h and 4min.
On the first day of the month, sunrise is at 7:08 am and sunset at 6:52 pm. On the last day of October, sunrise is at 7:42 am and sunset at 6:06 pm CDT.

Sunshine

In Grinnell, the average sunshine in October is 5.5h.

UV index

In Grinnell, the average daily maximum UV index in October is 2. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV rays for average individuals.
Note: In October, the average maximum UV index of 2 translates into the following recommendations:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Consider carefully! The reflective quality of snow can almost double the intensity of the Sun's UV radiation.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are October temperatures in Grinnell?

The high-temperature, in October, in Grinnell, records 59.9°F (15.5°C), while the low-temperature is 44.4°F (6.9°C). In July, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which factors the actual air temperature with the relative humidity, is estimated at 87.8°F (31°C).

What is the least humid month in Grinnell?

With an average relative humidity of 71%, October is the least humid month.

What is the average humidity in October in Grinnell?

The average relative humidity in October in Grinnell is 71%.

How many days does it rain in October in Grinnell?

In Grinnell, during October, the rain falls for 9.1 days and regularly aggregates up to 0.94" (24mm) of precipitation.

When does it start snowing in Grinnell?

October is the first month it typically snows in Grinnell, Iowa. Throughout October, in the average 0.5 snowfall days, it receives 0.31" (8mm) of snow.

What is the average length of the day in October in Grinnell?

In Grinnell, Iowa, the average day length in October is 11h and 4min.

What time are sunrise and sunset in October in Grinnell?

On the first day of October, sunrise is at 7:08 am and sunset at 6:52 pm. On the last day of the month, sunrise is at 7:42 am and sunset at 6:06 pm CDT.

How long on average sun shines in October in Grinnell?

The average sunshine duration in October in Grinnell is 5.5h.

What is the UV index intensity in October in Grinnell?

In Grinnell, the average daily maximum UV index in October is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in October
Grinnell, IA

Average temperature in October - Grinnell, IA
  • Average high temperature in October: 59.9°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (27°F).

  • Average low temperature in October: 44.4°F

The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (13.8°F).

Average pressure in October
Grinnell, IA

Average pressure in October - Grinnell, IA
  • Average pressure in October: 30.01"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 in October
Grinnell, IA

Average wind speed in October - Grinnell, IA
  • Average wind speed in October: 9.6mph

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (7mph).

Average humidity in October
Grinnell, IA

Average humidity in October - Grinnell, IA
  • Average humidity in October: 71%

The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is October (71%).

Average rainfall in October
Grinnell, IA

Average rainfall in October - Grinnell, IA
  • Average rainfall in October: 0.94"

The wettest months (with the highest rainfall) are May and June (1.97").
The driest month (with the least rainfall) is January (0.47").

Average rainfall days in October
Grinnell, IA

Average rainfall days in October - Grinnell, IA
  • Average rainfall days in October: 9.1 days

The month with the highest number of rainy days is June (15.1 days).
The month with the least rainy days is February (4.1 days).

Average snowfall in October
Grinnell, IA

Average snowfall in October - Grinnell, IA
  • Average snowfall in October: 0.31"

The month with the highest snowfall is January (1.81").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in October
Grinnell, IA

Average snowfall days in October - Grinnell, IA
  • Average snowfall days in October: 0.5 days

The month with the highest number of snowfall days is January (8.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in October /
Average sunshine in October
Grinnell, IA

Average daylight in October / Average sunshine in October - Grinnell, IA
  • Average daylight in October: 11h and 1min

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 12min).

  • Average sunshine in October: 5h and 3min

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 6min).

Average sunshine days in October
Grinnell, IA

Average sunshine days in October - Grinnell, IA
  • Average sunshine days in October: 19.8 days

The month with the most sunshine days is January (21.1 days).
The month with the least sunshine days is June (11.5 days).

Average UV index in October
Grinnell, IA

Average UV index in October - Grinnell, IA
  • Average UV index in October: 2

The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).

Average cloud cover in October
Grinnell, IA

Average cloud cover in October - Grinnell, IA
  • Average cloud cover in October: 37

The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is September (Cloud cover 29).

Average visibility in October
Grinnell, IA

Average visibility in October - Grinnell, IA
  • Average visibility in October: 6mi

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

Grinnell, Iowa, USA

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