This report describes the historical weather record at the Owatonna (Owatonna, Minnesota, United States) during 2012. This station has records back to August 1992.
Owatonna, Minnesota has a humid continental climate with warm summers and no dry season. The area within 25 mi of this station is covered by croplands (98%)
Daylight saving time (DST) was observed at Owatonna, Minnesota during 2012. There were two time changes during 2012:
2012 was a leap year and thus has 366 days rather than the normal 365. Leap years occur every fourth year and the extra day is always February 29th. In 2012 February 29th falls on a Wednesday.
The summer and winter solstices and the spring and fall equinoxes mark the passing of the seasons. They fall on nearly the same day each year, with differences of a day or two depending on the year. In 2012 they occurred on:
|Spring Equinox||Tuesday, 20 March 2012.|
|Summer Solstice||Wednesday, 20 June 2012.|
|Fall Equinox||Saturday, 22 September 2012.|
|Winter Solstice||Friday, 21 December 2012.|
The hottest day of 2012 was July 6, with a high temperature of 99°F. For reference, on that day the average high temperature is 81°F and the high temperature exceeds 88°F only one day in ten. The hottest month of 2012 was July with an average daily high temperature of 87°F.
Relative to the average, the hottest day was March 16. The high temperature that day was 81°F, compared to the average of 40°F, a difference of 40°F. In relative terms the warmest month was March, with an average high temperature of 58°F, compared to an typical value of 41°F.
The longest warm spell was from June 26 to July 19, constituting 24 consecutive days with warmer than average high temperatures. The month of July had the largest fraction of warmer than average days with 90% days with higher than average high temperatures.
The coldest day of 2012 was January 19, with a low temperature of -11°F. For reference, on that day the average low temperature is 7°F and the low temperature drops below -11°F only one day in ten. The coldest month of 2012 was January with an average daily low temperature of 15°F.
Relative to the average, the coldest day was October 12. The low temperature that day was 21°F, compared to the average of 41°F, a difference of 20°F. In relative terms the coldest month was September, with an average low temperature of 50°F, compared to an typical value of 51°F.
The longest cold spell was from September 20 to September 29, constituting 10 consecutive days with cooler than average low temperatures. The month of September had the largest fraction of cooler than average days with 57% days with lower than average low temperatures.
The longest freezing spell was from December 21 to December 31, constituting 11 consecutive days with temperatures strictly below freezing.
The clearest month of 2012 was July, with 90% of days being more clear than cloudy. The longest spell of clear weather was from June 23 to July 13, constituting 21 consecutive days that were clearer than they were cloudy.
The cloudiest month of 2012 was February, with 48% of days being more cloudy than clear. The longest spell of cloudy weather was from February 26 to March 4, constituting 8 consecutive days that were cloudier than they were clear.
This station reports the quantity of liquid precipitation but not observations of weather events in the area. For this reason, this section will only discuss the quantity of precipitation and not its type.
The day with the largest quantity of precipitation was June 14. That day saw 3.563" of liquid (or liquid equivalent) precipitation, compared to a median value of 0.110". The month with the most precipitation was May, with 7.673", compared to a median value of 2.907".
As determined by quantitative measurements, the longest dry spell was from March 13 to April 13, constituting 32 consecutive days with no measured precipitation. The month with the largest fraction of dry days was January, with 94% of days reporting no measured precipitation at all.
The month with the largest fraction of days with at least some measured precipitation was May, with 42% of days reporting some measured precipitation.
Either snow is exceptionally rare at this location or this station did not reliably report it during 2012.
Humidity is an important factor in determining how weather conditions feel to a person experiencing them. Hot and humid days feel even hotter than hot and dry days because the high level of water content in humid air discourages the evaporation of sweat from a person's skin.
When reading the graph below, keep in mind that the hottest part of the day tends to be the least humid, so the daily low (brown) traces are more relevant for understanding daytime comfort than the daily high (blue) traces, which typically occur during the night. Applying that observation, the least humid month of 2012 was September with an average daily low humidity of 16%, and the most humid month was January with an average daily low humidity of 66%.
But it is important to keep in mind that humidity does not tell the whole picture and the dew point is often a better measure of how comfortable a person will find a given set of weather conditions. Please see the next section for continued discussion of this point.
Dew point is the temperature below which water vapor will condense into liquid water. It is therefore also related to the rate of evaporation of liquid water. Since the evaporation of sweat is an important cooling mechanism for the human body, the dew point is an important measurement for understanding how dry, comfortable, or humid a given set of weather conditions will feel.
Generally speaking, dew points below 50°F will feel a bit dry to some people, but comfortable to people accustomed to dry conditions; dew points from 50°F to 68°F are fairly comfortable to most people, and dew points above 68°F are increasingly uncomfortable, becoming oppressive around 77°F.
To take some examples, and basing our categorization on the daily high dew point in 2012, January had 29 dry days, no comfortable days, and no humid days; April had 19 dry days, 11 comfortable days, and no humid days; July had no dry days, 14 comfortable days, and 17 humid days; and October had 25 dry days, 6 comfortable days, and no humid days.
The highest sustained wind speed was 34 mph, occurring on May 23; the highest daily mean wind speed was 24 mph (March 27); and the highest wind gust speed was 47 mph (May 4).
The windiest month was March, with an average wind speed of 12 mph. The least windy month was August, with an average wind speed of 6 mph.
Visibility is the maximum distance at which a given reference object or light can be clearly discerned. In the United States, visibilities that are greater than or equal to 10 miles are typically reported as 10 miles.
The day of 2012 with the lowest average visibility was February 1, with an average visibility of 0.9 mi. The month with the lowest average visibility was December, with an average visibility of 7.5 mi. With an average visibility of 9.8 mi, the month of June had the highest average visibility.
The cloud ceiling is the altitude of the lowest layer of clouds that are at categorized as broken (mostly cloudy) or overcast (cloudy). If no such cloud layer exists then the ceiling is unlimited and no value is reported.
The day of 2012 with the lowest average cloud ceiling was December 30, with an average cloud ceiling of 98'. The month with the lowest average cloud ceiling was December, with an average cloud ceiling of 2855'. The month of September has the highest average cloud ceiling, with an average cloud ceiling of 6993'.