May 2019 was wetter and warmer than normal. My max temp (76.7°) was 2.9° above normal and my min temp (59.7°) was even more significantly 7.9° above normal, resulting in the mean temperature (68.2°) to be 5.4° above normal. My total precipitation of 6.24″ was 1.97” above the newly computed normal precipitation May value for my station of 4.27. There were a lot of smaller amounts of daily precipitation leading to an above normal 13 days with measurable precipitation, Nine of the 13 days occurred during the first 16 days of the month, including two 4 day streaks of rainfall (1.88” from May 2-5 and 2.78” from May 10-13).

There were a few cooler than normal days during these wet periods, particularly from May 12-15 with generally max temps in the 50s and lows in the 40s (the lowest being 44.3° on the 15th). The rest of the month had seasonable to seasonably warm temperatures, highlighted by my first 90° max on the 29th. There were fourteen 80°+ max temps and fifteen 60°+ mins during the month.

There were 13 days with measurable precipitation, highlighted by the monthly maximum of 1.28″ on the 10th that started our wettest period of the month through the 13th that was detailed earlier There were two other notable precipitation days during the month (1.05” on the 5th and 0.93” on the 28th).

The highest barometric pressure reading of the month of 30.36” occurred on the 1st. The lowest reading was a rather modest 29.65” on the 29th on the hottest day of the month.

The highest dew point temperature reached during the month was 74° on the 19th and 28th. There were 8 days in May when dew point temps were 70° or higher, values I consider humid for May. My warmest air temperature of the month
(90.2°) was recorded during a particularly muggy period on the 29th. The lowest dew point temperature value was reached on the 14th (2nd coldest day of the month) when a value of 41° was reached.

May had 11 cloudy days, 13 partly cloudy days, and 7 clear/sunny days. There were 63 heating degree days and 162 cooling degree days during the month. There were 5 foggy days, 2 windy days, and 5 days with thunder.

Daily max/min temperatures varied as they usually do during the spring. My maximum temperature frequencies included 1 day over 90°, 14 days between 80° and 89°, 9 days between 70° and 79°, 4 days between 60° and 69°, and 3 days between 50° and 59°. On the minimum temperature frequency side of things, there were 4 days between 40° and 49°, 12 days between 50° and 59°, 13 days between 60° and 69° and 2 days above 70°. The coldest daily max temperature was 55.0° on the 13th while the warmest daily min temp of 71.3° was on the 20th.

The diurnal range daily monthly average was 19.0° (- 3.0°). Our greatest daily range of temperature was 27.3° on the 2nd (84.9°-57.6°) and 15th (71.6°-44.3°). We had a total of 11 days with daily ranges above 20°. Our lowest range of temperature was 5.2° (66.4°-61.2°) on the 8th. There were 5 total days with diurnal temperature ranges of less than 10° throughout the month, all occurring on or before the 13th of the month. .

May 2019 was a typical transitional month from spring to summer, with patterns during the month generally filling the bill quite well. No problems were experienced with my weather station during the month thank goodness.

Here is my data spreadsheet for May 2019, added July 5 2019

Rockville-2.8-WNW-MD-2019-05

MAY 2019 – ROCKVILLE 2.8 WNW MARYLAND – SUMMARY STATISTICS

Average high temperature 76.7° (+ 2.9°)
Average low temperature 59.7° (+ 7.9°)
Mean temperature 68.2° (+ 5.4°)

Precipitation 6.24″ (+ 1.97”)
Greatest daily amount (date) 1.28″ (10)
Greatest storm total (dates) 2.78” (10-13)
2019 year-to-date precipitation total 20.29″ (+3.57”)

Snowfall 0.0”
Seasonal snowfall total (final) 26.8″

High temperature for the month (date) 90.2° (29)
Low temperature for the month (date) 44.3° (15)

Highest barometric pressure (date) 30.36” (1)
Lowest barometric pressure (date) 29.65” (29)

Peak wind gust (date/direction): N/A

Heating degree days for the month: 63
Cooling degree days for the month: 162

Greatest diurnal range (date): 27.3° (2,15)
Least diurnal range (date) 5.2° (8)

Number of days:

Fog 5
Windy 2
Thunder 5
Snow 0
Sleet 0
Glaze 0
Cloudy 11
Partly Cloudy 13
Sunny/Clear 7
Max temp = 80° 15
Min temp < 50° 4
Min temp =< 32° 0
Precip = 0.01” 13