AUGUST 2019 MONTHLY SUMMARY AND SUMMARY STATISTICS ROCKVILLE 2.8 WNW MARYLAND
August 2019 was much wetter and a bit warmer than normal. My max temp (84.5°) was only 0.3° above normal but my min temp (67.6°) was more significantly 3.4° above normal, resulting in the mean temperature (76.0°) to be 1.8° above normal. My total precipitation of 7.63″ was 4.44” above the normal August value for my station of 3.19”. There were more days but generally smaller daily amounts of precipitation than in July leading to an about normal amount of 11 days with measurable precipitation, Nine of those eleven days fell during two generally wet periods from August 3-7 and August 18-23 During these two periods 7.17” was recorded (over 96% of the month’s total).
There were only one notable relatively cool periods (max temps below 80°) during the month, a total of 6 straight days from August 23rd-29th.The coolest August min temp of 59.4° was reached at the end of this streak on the 30th. We didn’t have much rain during this period (0.34”) but we did have a lot of clouds to help keep the temperatures down. Conversely, the hottest period of the month was just prior to this cooler period, from the 18th-20th with 3 straight days of max temps over 90, including the month’s hottest reading of 92.2° on the 18th.
There were 11 days with measurable precipitation, highlighted by the monthly maximum of 1.22″ on the 21st during a period of numerous thunderstorms on the stormiest period of the month (2.53” from the 20th-23rd) Other thunderstormy periods included the 3rd-4th (1.61”) and the 7th-8th (2.23”) Conversely there was one notably significant dry period during August when no rain fell (7 straight days from the 8th-14th). There was also a significantly dry period at the end of the month (8 days from the 24th-31st) when only one day had rain (0.31” on the 28th) July had a very similar dry spell on those same last 8 days of the month. With the generally wet month once again, these dry periods did not start showing any adverse effects on the vegetation in the immediate area.
The highest barometric pressure reading of the month of only 30.25” occurred on the 25th and 31st during the end of the month dry period. The lowest reading was 29.74” on the 7th and 8th occurred around the time of two consecutive thunderstormy days of over an inch each day on the 6th and 7th. This lowest reading was the same value as the lowest reading in July.
The highest dew point temperature reached during the month was 78° on the hottest day of the month on the 18th , a, in the middle of our most humid period of the month with 12 straight days with dew point temps over 70° There also was a 9 day streak of 70 or greater dew points on the first 9 days of the month. There were 22 days in July when dew point temps were 70° or higher, including 10 days at or above 75°, mostly during the middle third of the month. The lowest dew point temperature value was reached on the 24th when a value of 52° was reached. There were 8 days during the month when the dew point temps were in the 50s, most of which occurred during the previously discussed coolest period of the month. .
August had 10 cloudy days, 19 partly cloudy days, and only 2 clear/sunny days with an unusual higher amount of partly cloudy days due to numerous thunderstorm days during the month (9 with several multi-storm days) There were 0 heating degree days and 342 cooling degree days during the month. There were 8 foggy days, 7 windy days, and 9 days with thunder.
Once again daily max/min temperatures didn’t vary very much, a typical trend during the summer period. My maximum temperature frequencies included 5 days over 90°, 20 days between 80° and 89°, and 6 days between 70° and 79°. On the minimum temperature frequency side of things, there were 2 days below 60°, 14 days between 60° and 69° and 15 days 70° and above. The coldest daily max temperature was 72.6° on the cloudy 23rd while the warmest daily min temp of 73.9° was on the 13th, when the temps were muted due to high dew points and a lot of clouds.
The diurnal range daily monthly average was 17.0° (- 3.0°). Our greatest daily range of temperature was 26.1° on the 30th (85.5°-59.4°). We had a total of 8 days with daily ranges above 20°. Our lowest range of temperature was 7.6° (72.6°-65.0°) on the 23rd (our coolest max day of the month). There were only 3 total days with diurnal temperature ranges of less than 10° throughout the month, occurring on three of the many cloudy days during the month but not particularly rainy/stormy at all. .
August 2019 was a typical mid-summer month, with heat, humidity and numerous heavy thunderstorms predominating and only two significantly long dry spells. Incredible Hurricane Dorian formed during August and ravaged the Bahamas and the SE coast of the United States into early September, but spared my area of Maryland fortunately. .
Excel Data spreadsheet PDF file link for my station for August 2019: 2019-08-Rockville-2.8-WNW
AUGUST 2019 – ROCKVILLE 2.8 WNW MARYLAND – SUMMARY STATISTICS
Average high temperature 84.5° (+ 0.3°)
Average low temperature 67.6° (+ 3.4°)
Mean temperature 76.0° (+ 1.8°)
Precipitation 7.63″ (+ 4.44“)
Greatest daily amount (date) 1.22″ (21)
Greatest storm total (dates) 2.53” (20-23)
2019 year-to-date precipitation total 37.66″ (+ 10.96”)
High temperature for the month (date) 92.2° (18)
Low temperature for the month (date) 59.4° (30)
Highest barometric pressure (date) 30.25” (25,31)
Lowest barometric pressure (date) 29.74” (7,8)
Peak wind gust (date/direction): N/A
Heating degree days for the month: 0
Cooling degree days for the month: 342
Greatest diurnal range (date): 26.1° (30)
Least diurnal range (date) 7.6° (23)
Number of days:
Fog 8
Windy 7
Thunder 9
Cloudy 10
Partly Cloudy 19
Sunny/Clear 2
Max temp ≥ 90° 5
Min temp < 60° 2
Min temp => 70° 15
Precip ≥ 0.01” 11