Temperature
While simply one component of the overall “Weather”, temperatures certainly play an important role for both birds & birders in Virginia Beach. Long-term temperatures, precipitation, and other variables are what influence the climate of Virginia Beach as a whole. In turn, our climate is what causes our city’s specific habitats to exist. There’s a reason we have live oak scrub along the coastal portions of the city, which transitions towards mixed pine/oak woodlands farther inland. Birds are intimately bound to climates and each species has a certain habitat type that is preferred. Temperatures influence when breeding windows occur for each species, and they also impact arrival & departure dates for many species. Of course, temperatures also play an important role in birding, and knowing what is ‘expected’ throughout the year can often provide clarity to birders in terms of what species might be expected, as well as providing information on where to bird. Temperatures for the thirty-year NOAA climate period (1991-2020) are displayed below, so that birders may have an idea of what to expect this year when planning their outings. Months are broken down into Early (1st-10th), Mid (11th-20th) and Late (remainder). Conditional formatting (colors) have been set using Microsoft Excel to help visualize these numbers in terms of how warm, or how cool certain periods tend to be.
Using these tables, and the conditional color-coding that Microsoft Excel has allowed for, one can quickly pick up on outlier periods. Our coldest range over the thirty-year climate period occurred in Early January 2018, where the average daily lows were a frigid 18°F, and average daily highs barely reached above freezing to 33°F! That timeframe produced a remarkable number of bird sightings, due to the intense nor’easter-induced blizzard that impacted the city. Due to the freezing of almost all inland waterways in the city, and in areas north and west of here, the coast became a true haven for waterfowl. Species we don’t often see in numbers here during January became prevalent, like Canvasback, Common Goldeneye, Common Merganser & White-winged Scoter to name a few. Frozen waterways, due to the persistent sub-freezing temperatures, caused displacements among Rails and Waders as well, which had to seek out moving water wherever it could be found. Species like King & Virginia Rail, as well as Sora, were pushed out of Back Bay towards a small “stream” of water that stayed open near Little Island Park. A pair of wintering Least Bitterns that likely would have gone unnoticed otherwise, were also found here as a result. A full write-up of this period can be viewed on the website here: Early January 2018 Journal. On the opposite end of the spectrum, the highest average temperatures were achieved during the heat wave of Late July 2020, when daily highs came in at a sweltering 97°F and daily lows dropped only to 78°F. Of course, heat indices during that time were likely to be in excess of 100°F (perhaps even around 110°F) making for a stifling period that was difficult to be out birding in. With July being the prime month for ‘fall’, southbound shorebirds arriving back in Virginia Beach, most birding tends to be done in the open. All birders here understand just how difficult this birding can be in the heat of July & August!
The above table was assembled using data from the NOAA National Centers for Environmental Information, in conjunction with the National Weather Service (NWS) gauge located at Norfolk International Airport. Exact values will, of course, vary in different portions of Virginia Beach. However, Norfolk International Airport provided a continuous stream of weather data going back to 1 Jan 1946, so for long-term temperature analysis, it provides for unmatched coverage in our region. This information is always visible, in the public domain, located here: https://www.ncdc.noaa.gov/cdo-web/datasets/GHCND/stations/GHCND:USW00013737/detail.