2011 Edisto Island climatological summary

Here is the climatic summary for 2011 for Cooperative station Edisto Middleton Plantation (S.C. "Southern Division" in the NCDC Climatological Data publication). Edisto Middleton is on the inland side of Edisto Island, 6 miles from the ocean as the crow flies. Its climate is actually more typical of that of an "interior coastal" location like Charleston (airport), Beaufort and Savannah...as opposed to peninsular Charleston or the Edisto Beach State Park Coop site, which are true coastal sites.

As a brief preview, I can say that it was a dry year with a very warm summer. The only truly wet month was July with 10.20 inches of rain, and almost all of that fell on just 3 days. Rainfall in the other months was consistently a little below normal, with May, September and December all ending up well below. Total for the year was 36.51 inches, which is only about three-quarters the average annual rainfall. Meaurable rain fell on only 85 days (normal is 110).

From the end of April until almost the middle of July, only 2.9 inches of rain fell. This contributed to a period of well-above-normal early summer temperatures. The daily high temperature was 90+ for an amazing (for this close to the coast) 45 consecutive days (May 31 through July 14). The highest reading was 104 degrees on June 21, with 103 recorded on the 13th and 20th as well. On all of these days the sea breeze was held off until late afternoon...and with only an inch and a half of rain since April, the ground was parched. The instrumentation at the Edisto Middleton Coop station is a mercury in-glass maximum thermometer in a Cotton Region Shelter, backed up by a Nimbus MMTS.

This period in June was the hottest weather the area had experienced since August 1, 1999, when Charleston recorded its all-time high temperature of 105, a day on which gusty northwesterly winds kept the sea breeze at bay all day and carried those 100+ readings all the way to the beaches (and concidentally, the same day I was self-moving from my previous house to my current one). Interestingly, the minimum temperature that morning was 85 degrees (although cold outfow from thunderstorms just before midnight on the 2nd lowered the 24-hour minimum to 80 for the day). One of the forecasters commented that he knew we were in for a bad day when the temperature at 7 am was 85 degrees...with patches of dense fog! But the dew point dropped into the upper 50s and 60s during the afternoon.

Overall, there were 111 days with maximum temps at or above 90 degrees (121 days at Savannah), probably some kind of record, and over twice the normal number of such days.

The lowest temperature for the year was 21 degrees on January 14. There were 12 days with minimums of 32 or below - all occurring in January. It's unusual not to have any freezes in February or December, and we can usually expect a couple in March and maybe late November as well.