MONTHLY WEATHER DATA AND OBS - LAVALE MD JULY 2011 OBSERVER SCOTT LOHR DATA COMPILED AND PUBLISHED BY NATE MULLINS Special Observations: F=fog, T=thunder, H=hail, S=sleet, G=glaze, DW=damaging winds Observation time for this station is midnight. Temperature, °F Precipitation, In. Liquid Solid 7am DAY 24-hour Rain Snow/ Snow Special WEATHER Date Max Min Equiv Ice Depth Obs. SUMMARY 1 87 56 Fair & pleasant 2 91 54 Fair, cool AM, hot PM 3 90 70 T Partly cloudy, t-storms nearby 4 80 66 T Mostly cloudy, very brief PM shower 5 86 64 Mostly cloudy then partial clearing 6 90 64 Partly cloudy, hot 7 90 68 T Mostly cloudy, hot/humid, storms nearby 8 75 68 .53 Mostly cloudy, PM steady rain 9 88 65 Partly cloudy, warm 10 90 61 Partly cloudy, hot 11 95 67 .02 T Partly cloudy, very hot, weakening PM t-storms 12 91 75 Partly cloudy, hot, breezy 13 86 68 Variably cloudy, gusty N winds this PM 14 81 56 Fair & pleasant 15 80 55 Fair & pleasant 16 87 54 Fair & pleasant 17 90 62 Fair, hotter 18 92 70 Fair, hot, humid 19 92 75 .06 Pre-dawn shower, then mostly sunny, hot/humid 20 95 70 Partly cloudy, very hot & humid 21 100 70 Partly cloudy, extremely hot & humid 22 103 80 .01 T EXTREMELY HOT & HUMID, P. Cloudy, brief PM t-storm 23 97 75 Very hot & humid, fair skies 24 94 78 Very hot & humid, partly to mostly cloudy 25 85 71 Partly to mostly cloudy, not as hot 26 91 69 Fair, hot, less humid, breezy 27 90 63 Fair & very warm 28 93 64 .04 T Variable clouds, very hot, humid, brief PM t-storm 29 97 68 .01 T VERY hot & humid, very brief PM t-storm 30 93 74 Continued hot, fair skies, less humid 31 94 63 Sunny, very hot, low humidity AVG/SUM 90.1 66.5 0.67 0.0 - EXT 103 54 0.53 - - Date 22 16* 8 - - *=Also occurred on earlier dates Miscellaneous Stats Mean Monthly Temperature: 78.3°F (+5.5°F - HOTTEST JULY AND MONTH ON RECORD) Year precipitation to date: 27.36" (+2.82") Monthly precipitation departure: -3.02" (July average 3.69") Season snowfall to date: 0.0" Number of days with: Thunder 6 NOTES/SIGNIFICANT EVENTS 8: Only significant rainfall of the month, 0.53" fell, with a high of only 75. 11-12: Very hot high 95 on the 11th tied the 1988 record, record high min 75 on the 12th. *EXTREMELY HOT AND DRY STRETCH* 17-31: Incredible stretch of 90-degree days, 14 of 15 days hit 90 or higher, two 100+. ***INCREDIBLE RECORD-SETTING HEAT WAVE*** 20-24: EXTREME heat and humidity. High of 100 on the 21st breaks record of 99 in 1991 and is the 1st 100-degree reading since July 31, 1999. Low of 80 on the 22nd sets daily record and is the 2nd highest reading on record, as was record high of 103. The 22nd became the new hottest day on record, with an average of 91.5 F. Heat indeces were around 125, reaching the threshold for "extreme danger" on the heat index chart. This was followed by highs of 97 and 94 on the 23rd and 24th and a low of 78 on the 24th, actually not a record high min, since the station record high min 82 was set exactly one year ago, July 24, 2010. This will go down as one of the most severe heat waves in modern history. Even nearby mountains were well into the 90s. 28-29: Continued very hot, another 1988 record (97) tied on the 29th. On both evenings, big clusters of severe storms evaporated as they moved in, yielding only .05" rain. MONTHLY SUMMARY Incredibly HOT and DRY would sum up July 2011. 10 daily record highs were set this month, including the 1st 100-degree reading in 12 years on the 21st, followed by 103 on the 22nd, the 2nd highest reading on record, behind 105 on July 16, 1988. The heat this month was absolutely relentless, with 21 days reaching 90 or higher, tying monthly station records set in 1955 & 1999. 14 of the last 15 days were in the 90s or higher. 8 consecutive low temperatures were in the 70s, with one overnight low of 80 - on the 22nd, which set a new record high average temperature of 91.5 - the hottest day on record. Heat indeces were near 90, even overnight, and peaked around 125, perhaps the highest heat index reading on record. While the entire month was extremely hot, the large heat wave that broke out from about the 18th-24th was one of the most intense in recent history, especially considering the high humidities that pushed heat indeces way over 100 on many days. July 2011 became the hottest month on record with a mean temperature of 78.3 F, beating out the record of 77.8 F set only last year in July 2010. July was the 6th consecutive month with above normal temperatures. Every month in 2011, except January, has seen above average temps. There was little to no relief from the scorching heat, due to the lack of rainfall. Large systems of heavy rain and thunderstorms repeatedly approached the area from the northwest and evaporated when they crossed the Allegheny Front, many times reforming just to our east, where precipitation at many locations was actually near or above normal. A total of 0.67" of rain fell in July, the driest July and summer month on record. The excessive heat and obvious lack of moisture left the area resembling a high desert - it was unreal. Additional notes/records: 11: Daily record high 95 F tied with 1988. 12: Record high min 75 F, breaks record of 72 in 1993. 19: Record high min 75 F, previous record 72 in 2005. 21: Daily record high 100 F beats 1991's record of 99. 1st 100-degree reading since 7/31/1999. 22: Daily record high 103 F smashes previous record of 98 in 1987. This is the 2nd hottest reading at this location since records began in 1948. The hottest was 105 F on 7/16/1988. 22: Record high min 80 F smashes 1952 record of 75. Also the 2nd highest MIN reading on record. 22: HOTTEST DAY ON RECORD! Mean temp of 91.5 breaks record set last year 7/24/2010 (89.0 F). 23: Record high min 75 F tied with 1972. 24: Low of 78 ties 3 other dates for the 3rd warmest min on record, but is not a daily record, as last year (2010) had a min of 82 on this date, which was the warmest min temp on record. 29: Daily record high 97 F again ties with 1988. 30: Record high min 74 F. Old record was 69 in 1996. July 2011 is the *HOTTEST JULY AND MONTH ON RECORD* with a mean temperature of 78.3 F. July's mean max of 90.1 is the 2nd highest on record. 1999's 90.5 F mean max is still highest. July's mean min of 66.5 ties last July (2010) for the warmest mean min on record. July had 21 days reaching 90 or higher, tying the monthly records set in 1955 & 1999. July 2011 was also the DRIEST July AND summer month on record with only 0.67" of rainfall.