Climate and Average Weather Year Round at Birjand International Airport Iran

At Birjand International Airport, the summers are long, hot, arid, extremely windy, and clear and the winters are very cold, dry, and mostly clear. Over the course of the year, the temperature typically varies from 27°F to 95°F and is rarely below 17°F or above 102°F.

Based on the beach/pool score, the best time of year to visit Birjand International Airport for hot-weather activities is from early June to late August.

The hot season lasts for 4.1 months, from May 18 to September 20, with an average daily high temperature above 86°F. The hottest month of the year at Birjand International Airport is July, with an average high of 94°F and low of 69°F.

The cold season lasts for 3.2 months, from November 29 to March 3, with an average daily high temperature below 59°F. The coldest month of the year at Birjand International Airport is January, with an average low of 27°F and high of 51°F.

At Birjand International Airport, 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 at Birjand International Airport begins around May 17 and lasts for 5.3 months, ending around October 26.

The clearest month of the year at Birjand International Airport is August, during which on average the sky is clear, mostly clear, or partly cloudy 99% of the time.

The cloudier part of the year begins around October 26 and lasts for 6.7 months, ending around May 17.

The cloudiest month of the year at Birjand International Airport is March, during which on average the sky is overcast or mostly cloudy 34% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Birjand International Airport varies throughout the year.

The wetter season lasts 4.3 months, from December 5 to April 14, with a greater than 6% chance of a given day being a wet day. The month with the most wet days at Birjand International Airport is March, with an average of 3.4 days with at least 0.04 inches of precipitation.

The drier season lasts 7.7 months, from April 14 to December 5. The month with the fewest wet days at Birjand International Airport is September, with an average of 0.1 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone at Birjand International Airport is March, with an average of 3.4 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 12% on March 19.

Rainfall

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. Birjand International Airport experiences some seasonal variation in monthly rainfall.

The rainy period of the year lasts for 2.7 months, from January 16 to April 5, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain at Birjand International Airport is February, with an average rainfall of 0.7 inches.

The rainless period of the year lasts for 9.3 months, from April 5 to January 16. The month with the least rain at Birjand International Airport is July, with an average rainfall of 0.0 inches.

The length of the day at Birjand International Airport varies significantly over the course of the year. In 2024, the shortest day is December 21, with 9 hours, 59 minutes of daylight; the longest day is June 21, with 14 hours, 19 minutes of daylight.

The earliest sunrise is at 4:24 AM on June 12, and the latest sunrise is 2 hours, 12 minutes later at 6:36 AM on January 9. The earliest sunset is at 4:26 PM on December 4, and the latest sunset is 2 hours, 19 minutes later at 6:45 PM on June 29.

Daylight saving time (DST) is not observed at Birjand International Airport during 2024.

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The perceived humidity level at Birjand International Airport, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed at Birjand International Airport experiences extreme seasonal variation over the course of the year.

The windier part of the year lasts for 3.1 months, from June 7 to September 12, with average wind speeds of more than 13.5 miles per hour. The windiest month of the year at Birjand International Airport is July, with an average hourly wind speed of 19.1 miles per hour.

The calmer time of year lasts for 8.9 months, from September 12 to June 7. The calmest month of the year at Birjand International Airport is November, with an average hourly wind speed of 7.6 miles per hour.

The predominant average hourly wind direction at Birjand International Airport varies throughout the year.

The wind is most often from the east for 5.6 months, from May 3 to October 22, with a peak percentage of 60% on June 25. The wind is most often from the west for 6.4 months, from October 22 to May 3, with a peak percentage of 38% on January 1.

To characterize how pleasant the weather is at Birjand International Airport 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 Birjand International Airport for general outdoor tourist activities are from early May to mid June and from late July to early October, with a peak score in the second 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 Birjand International Airport for hot-weather activities is from early June to late August, with a peak score in the second week of July.

Methodology

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.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season at Birjand International Airport typically lasts for 7.3 months (223 days), from around March 21 to around October 30, rarely starting before March 4 or after April 9, and rarely ending before October 8 or after November 21.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms at Birjand International Airport should appear around March 2, only rarely appearing before February 15 or after March 21.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 3.7 months, from May 7 to August 30, with an average daily incident shortwave energy per square meter above 7.8 kWh. The brightest month of the year at Birjand International Airport is June, with an average of 8.8 kWh.

The darker period of the year lasts for 3.1 months, from November 5 to February 10, with an average daily incident shortwave energy per square meter below 4.5 kWh. The darkest month of the year at Birjand International Airport is December, with an average of 3.4 kWh.

For the purposes of this report, the geographical coordinates of Birjand International Airport are 32.898 deg latitude, 59.266 deg longitude, and 4,911 ft elevation.

The topography within 2 miles of Birjand International Airport contains only modest variations in elevation, with a maximum elevation change of 443 feet and an average elevation above sea level of 4,968 feet. Within 10 miles contains only modest variations in elevation (3,891 feet). Within 50 miles also contains extreme variations in elevation (5,682 feet).

The area within 2 miles of Birjand International Airport is covered by bare soil (79%), within 10 miles by bare soil (50%) and shrubs (22%), and within 50 miles by bare soil (53%) and shrubs (30%).