If June seemed hot, it was!
Posted July 1, 2009
Now that we've wrapped up what struck a lot of us as a pretty toasty June, we can fully summarize the numbers that show it ranked as one of the warmest on record at the Raleigh-Durham airport. At least in the last few days of the month, the low and mid 90s-range temperatures were paired with dew points that hovered in the upper 40s to mid-50s, indicating low humidity levels that mitigated the discomfort associated with the heat.
At any rate, here's how the numbers ended up. We averaged 78.3 degrees for the June just ended, which is 3.6 degrees above normal. That normal is 74.7 degrees, based on the 30-year mean for the period 1971-2000, and the standard deviation associated with that statistic is +/- 2.3 degrees.
For comparison purposes, the coolest June on record at RDU was 1979, when the average temperature was 69.8 degrees, while we just had our warmest June ever one year ago, with the 2008 average of 80.7 topping the 66-year list. This year's 78.3 comes in fifth.
Another mark of the hot June was 18 days that reached 90 degrees or higher. Again, that's well above the normal value of 8.4, and on the list of 66 years' data from RDU, it ties for fifth place on a scale that runs from a high of 23 days in 1952 down to an absurdly mild June of 1972, in which not a single 90-degree reading was recorded!
All in all then, one of the hotter Junes we've had here, though notably short of the record we set last year. Hot weather and dry conditions sometimes go hand in hand, and it was a fairly dry June as well, with the airport recording 2.34 inches of rain, about 1.08 inch below normal. Of course, rainfall around the region can be highly variable given the convective nature of rain this time of year, and we know a few spots in the area (central Wake, northern Granville and southern Nash counties for example) had as much as 4-8 inches for the month, while some others (Lee, southern Johnston, southeast Chatham among them) received less than 1.5 inches.
How the rest of the summer will turn out remains a toss-up in the absence of strong short-term climate-forcing signals, with the Climate Prediction Center indicating "equal chances" for normal, below normal, or above normal temperature and precipitation through the remainder of the season.