Average Weather in Smyrna Delaware, United States
In Smyrna, the summers are warm and muggy, the winters are very cold and windy, and it is wet and partly cloudy year round. Over the course of the year, the temperature typically varies from 26°F to 86°F and is rarely below 14°F or above 94°F.
Based on the tourism score, the best times of year to visit Smyrna for warm-weather activities are for the entire month of June and from early August to late September.
The hot season lasts for 3.5 months, from May 31 to September 16, with an average daily high temperature above 77°F. The hottest day of the year is July 21, with an average high of 86°F and low of 70°F.
The cold season lasts for 3.2 months, from December 3 to March 8, with an average daily high temperature below 50°F. The coldest day of the year is January 30, with an average low of 26°F and high of 41°F.
Average High and Low Temperature
Average Hourly Temperature
In Smyrna, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.
The clearer part of the year in Smyrna begins around July 1 and lasts for 4.5 months, ending around November 18. On September 23, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 65% of the time, and overcast or mostly cloudy 35% of the time.
The cloudier part of the year begins around November 18 and lasts for 7.5 months, ending around July 1. On January 5, the cloudiest day of the year, the sky is overcast or mostly cloudy 52% of the time, and clear, mostly clear, or partly cloudy 48% 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 Smyrna varies throughout the year.
The wetter season lasts 3.7 months, from May 4 to August 27, with a greater than 30% chance of a given day being a wet day. The chance of a wet day peaks at 39% on August 3.
The drier season lasts 8.3 months, from August 27 to May 4. The smallest chance of a wet day is 22% on October 20.
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 39% on August 3.
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. Smyrna experiences some seasonal variation in monthly rainfall.
Rain falls throughout the year in Smyrna. The most rain falls during the 31 days centered around September 27, with an average total accumulation of 3.6 inches.
The least rain falls around February 7, with an average total accumulation of 2.1 inches.
Average Monthly Rainfall
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Smyrna experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 4.1 months, from November 23 to March 25, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around January 30, with an average total liquid-equivalent accumulation of 0.6 inches.
The snowless period of the year lasts for 7.9 months, from March 25 to November 23. The least snow falls around July 24, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Smyrna varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 24 minutes of daylight; the longest day is June 21, with 14 hours, 56 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:35 AM on June 14, and the latest sunrise is 1 hour, 57 minutes later at 7:32 AM on November 3. The earliest sunset is at 4:39 PM on December 7, and the latest sunset is 3 hours, 54 minutes later at 8:33 PM on June 28.
Daylight saving time (DST) is observed in Smyrna 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
Smyrna experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 4.2 months, from May 23 to September 30, during which time the comfort level is muggy, oppressive, or miserable at least 17% of the time. The muggiest day of the year is August 2, with muggy conditions 67% of the time.
The least muggy day of the year is February 11, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
The average hourly wind speed in Smyrna experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 6.8 months, from October 16 to May 10, with average wind speeds of more than 9.2 miles per hour. The windiest day of the year is February 26, with an average hourly wind speed of 11.3 miles per hour.
The calmer time of year lasts for 5.2 months, from May 10 to October 16. The calmest day of the year is August 12, with an average hourly wind speed of 7.1 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Smyrna varies throughout the year.
The wind is most often from the south for 1.9 months, from May 8 to July 4 and for 2.7 months, from July 15 to October 7, with a peak percentage of 37% on August 2. The wind is most often from the west for 1.6 weeks, from July 4 to July 15 and for 7.0 months, from October 7 to May 8, with a peak percentage of 36% on July 6.
Smyrna is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences significant seasonal variation over the course of the year.
The time of year with warmer water lasts for 3.5 months, from June 20 to October 3, with an average temperature above 68°F. The day of the year with the warmest water is August 9, with an average temperature of 75°F.
The time of year with cooler water lasts for 3.6 months, from December 19 to April 6, with an average temperature below 45°F. The day of the year with the coolest water is February 11, with an average temperature of 38°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is in Smyrna 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 Smyrna for general outdoor tourist activities are for the entire month of June and from early August to late September, with a peak score in the first 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 Smyrna for hot-weather activities is from late June to early September, with a peak score in the third week of July.
The growing season in Smyrna typically lasts for 7.0 months (215 days), from around April 2 to around November 3, rarely starting before March 17 or after April 19, and rarely ending before October 18 or after November 20.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in Smyrna should appear around March 28, only rarely appearing before March 11 or after April 14.
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 3.8 months, from April 26 to August 21, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest day of the year is June 23, with an average of 6.9 kWh.
The darker period of the year lasts for 3.1 months, from November 6 to February 9, with an average daily incident shortwave energy per square meter below 2.9 kWh. The darkest day of the year is December 23, with an average of 1.9 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Smyrna are 39.300 deg latitude, -75.605 deg longitude, and 30 ft elevation.
The topography within 2 miles of Smyrna is essentially flat, with a maximum elevation change of 49 feet and an average elevation above sea level of 25 feet. Within 10 miles is also essentially flat (85 feet). Within 50 miles is essentially flat (761 feet).
The area within 2 miles of Smyrna is covered by cropland (71%) and artificial surfaces (29%), within 10 miles by cropland (51%) and trees (25%), and within 50 miles by cropland (37%) and trees (26%).
This report illustrates the typical weather in Smyrna, 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 5 weather stations near enough to contribute to our estimation of the temperature and dew point in Smyrna.
For each station, the records are corrected for the elevation difference between that station and Smyrna 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 Smyrna is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Smyrna and a given station.
The stations contributing to this reconstruction are: Dover Air Force Base (49%, 22 kilometers, southeast); New Castle Airport (19%, 42 kilometers, north); Millville Municipal Airport (16%, 46 kilometers, east); Martin State Airport (9%, 70 kilometers, west); and Thomas Point Coast Guard Station (8%, 73 kilometers, southwest).
Time zones for aiports and weather stations are provided by AskGeo.com .