Average Weather in Spiro Oklahoma, United States
In Spiro, the summers are hot and muggy; the winters are short, very cold, and wet; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 31°F to 94°F and is rarely below 18°F or above 101°F.
Based on the tourism score, the best times of year to visit Spiro for warm-weather activities are from early May to late June and from mid August to mid October.
The hot season lasts for 3.4 months, from June 4 to September 17, with an average daily high temperature above 85°F. The hottest day of the year is July 25, with an average high of 94°F and low of 72°F.
The cold season lasts for 2.9 months, from November 26 to February 23, with an average daily high temperature below 59°F. The coldest day of the year is January 7, with an average low of 31°F and high of 50°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
In Spiro, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Spiro begins around June 10 and lasts for 5.0 months, ending around November 8. On October 5, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 72% of the time, and overcast or mostly cloudy 28% of the time.
The cloudier part of the year begins around November 8 and lasts for 7.0 months, ending around June 10. On February 17, the cloudiest day of the year, the sky is overcast or mostly cloudy 48% of the time, and clear, mostly clear, or partly cloudy 52% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Spiro varies throughout the year.
The wetter season lasts 2.8 months, from April 8 to July 1, with a greater than 31% chance of a given day being a wet day. The chance of a wet day peaks at 44% on May 21.
The drier season lasts 9.2 months, from July 1 to April 8. The smallest chance of a wet day is 18% on January 12.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 44% on May 21.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Spiro experiences significant seasonal variation in monthly rainfall.
Rain falls throughout the year in Spiro. The most rain falls during the 31 days centered around May 11, with an average total accumulation of 5.4 inches.
The least rain falls around January 21, with an average total accumulation of 2.3 inches.
Average Monthly Rainfall
The sliding 31-day liquid-equivalent quantity of snowfall in Spiro does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Spiro varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 47 minutes of daylight; the longest day is June 21, with 14 hours, 32 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 6:03 AM on June 13, and the latest sunrise is 1 hour, 39 minutes later at 7:41 AM on November 3. The earliest sunset is at 5:05 PM on December 5, and the latest sunset is 3 hours, 31 minutes later at 8:37 PM on June 29.
Daylight saving time (DST) is observed in Spiro during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
Spiro experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 4.7 months, from May 10 to October 1, during which time the comfort level is muggy, oppressive, or miserable at least 22% of the time. The muggiest day of the year is July 22, with muggy conditions 87% of the time.
The least muggy day of the year is January 13, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
The average hourly wind speed in Spiro experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 7.1 months, from October 20 to May 22, with average wind speeds of more than 6.0 miles per hour. The windiest day of the year is March 23, with an average hourly wind speed of 7.5 miles per hour.
The calmer time of year lasts for 4.9 months, from May 22 to October 20. The calmest day of the year is August 3, with an average hourly wind speed of 4.6 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Spiro varies throughout the year.
The wind is most often from the north for 6.0 days, from January 23 to January 29, with a peak percentage of 32% on January 28. The wind is most often from the south for 12 months, from January 29 to January 23, with a peak percentage of 33% on January 1.
Best Time of Year to Visit
To characterize how pleasant the weather is in Spiro throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best times of year to visit Spiro for general outdoor tourist activities are from early May to late June and from mid August to mid October, with a peak score in the third week of September.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Spiro for hot-weather activities is from early June to early September, with a peak score in the first week of July.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
The growing season in Spiro typically lasts for 7.5 months (229 days), from around March 24 to around November 8, rarely starting before March 1 or after April 16, and rarely ending before October 19 or after November 29.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in Spiro should appear around February 17, only rarely appearing before January 31 or after March 6.
Growing Degree Days
The average daily incident shortwave solar energy experiences significant seasonal variation over the course of the year.
The brighter period of the year lasts for 4.1 months, from April 23 to August 27, with an average daily incident shortwave energy per square meter above 6.1 kWh. The brightest day of the year is July 12, with an average of 7.0 kWh.
The darker period of the year lasts for 3.0 months, from November 8 to February 7, with an average daily incident shortwave energy per square meter below 3.4 kWh. The darkest day of the year is December 23, with an average of 2.5 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Spiro are 35.241 deg latitude, -94.620 deg longitude, and 459 ft elevation.
The topography within 2 miles of Spiro contains only modest variations in elevation, with a maximum elevation change of 200 feet and an average elevation above sea level of 479 feet. Within 10 miles contains only modest variations in elevation (558 feet). Within 50 miles contains significant variations in elevation (2,349 feet).
The area within 2 miles of Spiro is covered by cropland (81%) and artificial surfaces (10%), within 10 miles by cropland (84%) and trees (11%), and within 50 miles by trees (58%) and cropland (36%).
This report illustrates the typical weather in Spiro, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Spiro.
For each station, the records are corrected for the elevation difference between that station and Spiro according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Spiro is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Spiro and a given station.
The stations contributing to this reconstruction are: Robert S Kerr Airport (36%, 25 kilometers, south); Fort Smith Municipal Airport (34%, 25 kilometers, northeast); and Sallisaw Municipal Airport (30%, 27 kilometers, northwest).
Time zones for aiports and weather stations are provided by AskGeo.com .