"It turned out to be a very hot summer in Philadelphia." So claim the authors of a recent monograph on the Convention. Writers have always watched Philadelphia's weather during the summer of 1787 and have, with few exceptions, described it as hot and oppressive, apparently because the heroic stature of the framers seems to require them to have conquered the elements as well as the political crisis in the nation. Farrand did not publish meteorological records for the summer of 1787; the closest approximation is an edition of William Samuel Johnson's laconic journal (III, 552-54). Research for the present supplement uncovered three detailed accounts of Philadelphia's summer weather which, because of the interest in the subject, are published in tabular form below. The entries under Morris are from a diary at the Hagley Museum and Library kept by the Philadelphia brewer Thomas Morris. Jacob Hiltzheimer, owner of a livery stable and other businesses in Philadelphia, was a member of the Pennsylvania Assembly; his diary is at the American Philosophical Society. Peter Legaux was a French immigrant who owned a farm and practiced viticulture at Spring Mill, thirteen miles northwest of Philadelphia. A student of Jean Andre DeLuc, the Swiss-born geologist and meteorologist, Legaux kept detailed meteorological records from 1786 to 1827. His observations for 1787 were published at the end of each month's issue of the Universal Asylum and Columbian Magazine, a Philadelphia literary magazine, from which they are printed here. Only selected items from Legaux's records are used. His full records, published in the Universal Asylum, contain each day's mean temperature in Fahrenheit and Reaumur, barometric readings, wind directions, amounts of precipitation, and even the frequency of appearances of the aurora borealis. In using Legaux's readings it should be remembered that he gives mean temperature and that all his information was recorded at his farm, not in downtown 1. James and Christopher Collier, Decision in Philadelphia: The Constitutional Convention of 1787 (New York, 1986)5 74-75- 325 326 SUPPLEMENT TO FARRAND'S RECORDS Philadelphia. Each month Legaux noted the highest and lowest temperature readings; these are included at the appropriate dates. Using Legaux's and other records, David M. Ludlum of the American Weather History Center compiled the following statistics on Philadelphia's weather during the summer of 1787: Average temp. Depart. normal Maximum Minimum Rainfall Depart. normal May 62.0 +0.7 80.i 34.1 4.96 +0.92 June 70.7 +1.0 93.8 45.0 1.88 -2.11 July 72.4 -4-I 96.0 45.7 3.09 -0.97 Aug. 74.5 -0.4 95.0 50.0 5.18 +0.95 Sept. 64.7 -1.7 93-9 36.5 2.62 -1.02 Ludlum calculated "normal" temperature and rainfall by using the Pennsylvania Hospital Records, 1825-71. He concluded that "in general terms Philadelphia enjoyed a cool summer in 1787."2 It is, perhaps, not without interest to compare these findings with a recent discovery that, despite the heat in which the imaginations of generations of writers have enveloped Philadelphia on July 4, 1776, Independence Day was also cool.' 2. Unpublished paper in author's possession. It is obvious, however, from letters in the new supplement that the impact of temperature was subjective; what to one person was hot was to another pleasant. 3. Paul H. Smith, "Time and Temperature: Philadelphia, July 4, 1776," Quarterly Journal of the Library of Congress 33 (October 1976): 297-98. Hiltzheimer Morris Legaux Some Rain in the Morning Some Rain in the Morning Clear & Pleasant Cloudy in forenoon, Clear in the Afternoon Clear in forenoon, in the afternoon . . . a gust coming on fast, . . . [later] it began to rain Clear Last Night, had a Smart Shower of Rain with Some Thunder a Gust in the Afternoon Clear & Pleasant Rain, in the Afternoon Cloudy and dull with driz'ling Rain at times Wind N. E. yet it cleared away at Night it was mild clear & serene Morning & so continued through the day 'tho the wind continued N. East foggy Morning, clear afterwards & pleasant, & in Evening a small Shower some Rain afternoon, & a Gust a little before Noon pleasant Weather gusty & uncertain weather, with Thunder about Noon Wind N. W. &cool Wind N. & Rain, & in the Evening clear &cool Wind southerly & pleasant it look'd very likely to rain in the Morning but clear'd away rain (& pretty much of it) fell nearly all day 56.9°; Rainy 63.2°; Overcast, fair 61`); Fog, very fair 66°; Fog, fair, thunder, rain 67.2°; Overcast, rain, thunder, storm 67.10; Very fair 67.2°; Very fair, rain, storm 60°; Very fair 60°; Overcast, rainy, changeable 60.2°; Fair, rainy 64.8°; Overcast, wet, cloudy, fair 59°; Overcast, rain May 14 May is May 16 May 17 May i8 May 19 May 20 May 21 May 22 May 23 Cloudy, forenoon . . . afternoon had Several Showers of Rain May 24 Cloudy, a little Rain May 25 rain All Day Hiltzheimer Morris Legaux May 26 May 27 May 28 May 29 May 30 May 31 June I June 2 June 3 June 4 June 5 Clear Cloudy, after Drops of Rain in the Morning Clear but not warme Clear forenoon The Wind South east, Rain All Day Cloudy and Cool enough to sit by the Fire Cloudy & Cool Cloudy . . . Rain toward evening, and Still Cold enough to Sit by the Fire Cloudy, with some rain Clear Cool enough to Sit by the Fire Clear & Pleasant in the forenoon cool & Wind N. W. pleasant 'tho cool for the Season & rather windy weather ditto pleasant weather much Rain, wind S. East there was a smart Shower in the Morning, the weather soon after clear'd up & the rest of the day was fine pleasant but rather cool cool Morning, & I think there must be frost. Fire seems necessary, & we have kept one in the Parlour Morng. & Eveng. & sometimes throughout the day for the most part of the Spring cool Wind from N. E. with flying Clouds & Rain in the Morning; in the Evening it clear'd at N. W. & was (I had almost said) cold clear &cool wind pretty high (Westerly) pleasant. . . . In the Evening it rained 57•30; Fair 54.50; Overcast, cloudy, cold 54.7°; Fair 59"; Fog, very fair 58.8"; Overcast, rain 69.7°; Thunder, rain 69"; Overcast, cold, fair 53.3"; lowest temp. of June, 45°; Overcast, cold, fair 54.8°; Rain, after fair, cold 570; Fair, cold, windy 63.2.; Fair, overcast, rain June 6 Rain Most All day dull Morning Wind N. E. & about ii 59.2°; Fog, overcast, wet, rain o'clock it began to rain &continued throughout the Day June 7 Rain variable Weather, Showers frequent 64°; Idem. June 8 Cloudy Clear & fine weather, wind N. W. in 63.2°; Fair, cloudy the Morng. clouded over before Noon & so continued most of the day. June 9 Very fine Haymaking weather 72.4°; Fair, warm June 10 Clear & Pleasant warmer than of late 72.4°; Fog, sun, fair June ii Clear & warme very pleasant 76°; Fair June 12 Clear & warme fine Hay weather 7j0; Fog, after fair June 13 Clear and Pleasant warm weather, the Thermometer at 73.5°; Fog, fair Noon 80 degrees June 14 Clear & Pleasant Warm & dusty, Therm. 84 77°; Fair June 15 Pleasant Ditto . . . 86 81.3°; highest temp. of June, 93°; Fair June 16 easterly wind &cooler, Thermometer 76.7°; Overcast, fair 76 June 17 Cloudy and a Very little rain 68°; Rain, clouds, fair Hiltzheimer Morris Legaux June 18 In the afternoon . . . Shower of rain June 19 Clear & warme June 20 Clear June 21 two Small Showers of rain June 22 much Thunder & Lightning, last Night with Heavy rain June 23 Clear & warme June 24 little rain June 25 Rain in the Morning, as well as last Night. Pleasant in the afternoon June 26 Clear & Pleasant June 27 Clear & warme June 28 Clear and Pleasant forenoon June 29 Cloudy, and a Very little rain in the Morning June 30 Clear & warme pleasant Weather very pleasant, Wind Easterly Weather sultry with a smart Shower afternoon a heavy thundergust in last Night with Rain. This Day cool & pleasant The weather was pleasant a Shower afternoon 3 o'clock A good deal of Lightning & Thunder in last Night with Rain. It also rained smartly this Morning pleasant Weather pleasant ditto wind N. E. Weather warm 770; Rain fog, clouds and storm 73•50; Fair 76°; Fog, fair and clouds 72.4°; Fog, clouds, rain, storm 76.5°; Fair, warm 76°; Fair 750; Fair, small rain 77•30; Fair, windy 72°; Idem. 78°; Rain, then fair 70.8°; Very fair 70.7°; Overcast, fair 73.5°; Idem. July 1 Cloudy. Rain several times, but Very little pleasant for the Season 73.7°; Overcast July 2 Cloudy Close & Very warme Foggy Morng. hot Sun afterwards 79.2°; Fog, cloudy, warm July 3 Very warm weather. Thermometer 90 degrees 85.8°; highest temp. of July, 96°; Very fair July 4 Clear & warme Wind N. West & pleasant for the 77-4°; Idem. Season July 5 Clear & warme forenoon 74.8°; Fair, clouds July 6 Very warme 76°; Very fair July 7 Very warme 74.5°; Idem. July 8 Very warme, a Small Springle of rain in the afternoon 79.2°; Idem, warm July 9 Warme . . . after Night had Much 8i°; Idem. Thunder, but Little rain July m Very warme 76°; Idem. July ii Cloudy 75°; Overcast, then fair July 12 Clear & warme 77°; Cloudy, fair July 13 Clear and Cool, but Very Dusty 71.1°; Very fair, aur. bor. July 14 Windy & Very Dusty 6i.5°; lowest temp. of July, 45.7°; Idem. Hiltzheimer Morris Legaux July 1 5 64°; Fair, overcast, rain July 16 had a Smart Shower of rain Last Night, and an other to day at Noon 74.20; Overcast, thunder, rain, fair July 17 Clear & Pleasant 66.8°; Very fair July 18 Clear & Pleasant 63.3°; Idem. July 19 In the Afternoon had a Small Shower of rain A small Shower after dinner 66.8°; Overcast July 20 Clear Wind N. East and cloudy in the 68.5°; Clouds, rainy Morning, afterward clear & pleasant Weather July 2! Clear & Pleasant weather the same 73°; Fair July 22 Warme Therm. 80: rather warmer than lately 720; Overcast, fair July 23 Very warme warm Weather; Therm. 83. In the 75.4°; Fair Evening threat'ned Rain but went over July 24 Very warme Wind N. East in the Morning, but soon changed to S. West &clear'd away 770; Overcast, wet, fair July 25 had Several Showers of rain fore & afternoon some Rain about Noon, Wind S. E., & a very fine refreshing Rain after 74.6°; Overcast, thunder, rain Dinner, which continued most of the Afternoon July 26 Had a Smart Shower of rain in the Cloudy most of the Day & some Rain 64°; Rainy Morning July 27 Clear, Cool & Very Pleasant Clear & very pleasant Weather 7J0; Cloudy July 28 Cloudy cool for the Season, Rain in Evening 70.2°, Overcast . . . Wind N. East July 29 Rain Last Night, and some this Wind N. E. &cool. Cloudy without 67.8°, Idem. Morning Rain July 30 Cloudy and uncommonly Cool wind N. E. & [ditto?] 67.2°; Idem. July 31 Cloudy & Some rain, and Quite Cool at the time Wind N. E. & more like Fall than Midsummer 66.5°, Idem. August 1 Cloudy, Cool, & some Rain Wind yet N. East with some Rain in the 65.7°, Rain Morning &cloudy all day August 2 Clear, and Much Warmer Wind veering around to S. West the 74.7°, Fair, cloudy Weather for the greater part of the day was clear & in the Sun warm. The Eveng. pleasant August 3 Clear warme & Pleasant Hot Sun 77°, highest temperature of August, 95°, Very fair and warm August 4 Clear & warme 82.8°, Idem. August 5 Very warme Summer Weather, Therm. 82 79.8°, Idem. August 6 Rain in the Morning, afternoon Very warme Wind S. E. and rainy in the Morng. after 10 o'Clock clear & warm 73.8°, Rain, then fair Hiltzheimer Morris Legaux August 7 Very Close & warme with a few Drops of rain at times Foggy Morning, afterwards clear & warm 770; Overcast, fair August 8 Very Foggy and Close in the The same 800; Fog, fair, warm Morning. afterward, exceeding warme August 9 Very close & warme, Several Showers of rain Rain afternoon with much Lightning & Thunder at Night 790; Overcast, rain, thunder August m Much lightning last Night and heavy Rain, to Day Cloudy and Close with Rain in last Night, & several Showers this day 76.6°; Cloudy, rainy Several Showers of rain in the evening August I I Clear & warme clear & pleasant Weather for Summer 73.8°; Fair August 12 Clear & Pleasant Ditto, but hot in the Sun 79.2°; Idem. August 13 Clear & warme the same 78 . 4°; Idem. August 14 Very warme very warm. Therm. 85 8 2°; . Idem. August is Warme forenoon more Air & pleasanter than yesterday. Rain in Evening with Lightning & 84.8°; Idem, windy, storm, thunder Thunder August i6 Clear Cool & Pleasant pleasant out of the Sun 74•30; Fair August 17 Cloudy & Some rain Pleasant Morning; cloudy Afternoon & some Rain 63°; Dew, overcast, rain August 18 August 19 August 20 August 21 August 22 August 23 August 24 August 25 August 26 August 27 August 28 August 29 Clear and Pleasant Clear & Pleasant Rain . . . Very hard Shower of rain at Night Cloudy Close & warme . . a Smart Shower of rain at Night Clear & Pleasant Clear & warme Clear and Very Warme Clear & Very warme Cool & Pleasant Rain Rain Clear cool, airy & pleasant weather moderate Wind S. E. &cloudy, about m o'Clock it began to rain &continued violently through the day & Evening cloudy at times with some Rain seasonable weather Wind N. W. & reasonably pleasant weather weather hot hot weather. Therm. 85 moderate weather, Wind N. W. Wind N. E. cloudy &cool with Rain in the Morning wind easterly with small Rain remarkably damp, close & unwholesome weather, some Rain with Lightning in the afternoon 74.8°; Cloudy, high wind, fair 68°; lowest temperature of August, 50°; Fair 67.8°; Rain 79.2°; Fair, rain, thunder 74°; Fair 74.8°; Idem. 75°; Idem. 81.3'; Very fair and warm 73.1°; Cloudy, windy 60°; Overcast, rain 65.6°; Idem. 80.2°; Very fair, thunder, and rain Hiltzheimer Morris Legaux August 30 August 31 September 1 September 2 September 3 September 4 September 5 September 6 September 7 September 8 September 9 September 10 September ii Little rain early in the Morning Clear & Pleasant Rain Most all Day Clear & Pleasant Clear & Pleasant Clear Clear in the Afternoon Clear & Pleasant Clear & Pleasant Clear & Pleasant in the afternoon . . . it was exceeding warme at the Same time, the wind being from the West, which was no Benefit to the room up Stairs Exceeding warme rain in the Morng. very pleasant Evening pleasant Weather, Wind NW. & N. E. Wind easterly with constant Rain from 2 o'Clock P. M. until Evening dull till near Noon, when the Weather clear'd & was pleasant pleasant Weather Ditto wind N. W. &cool, out of the Sun cool Morning & pleasant throughout Ditto warm Sun Therm. 82 degrees Weather oppressively hot, Therm. 85 [?] 72.8*; Overcast 64.3°; Fair, cloudy 64.7°; Overcast, rain 68°; Overcast, windy 65.3°; Fair 64.9°; Fair, then clouds 73.5°; Fog, fair, clouds, overcast 72.2°; Very fair 61°; Cloudy, then fair 64°; Overcast 72.5°; Very fair, and warm 74.2°; Overcast, windy, fair 80.9°; highest temperature of September, 93.9°; Very fair September 1 2 September 13 September 14 Very warme Exceeding close & warme Last Night—this Morning had alittle rain Rain Last Night, Close & Very warme today at Night had Some thunder, with Much Lightning, and heavy rain hot weather Therm. 87V. Rain in the Morning, & rather cooler all day than the three last Rain in last Night, the day at Times clear & Sun powerful. In the Evening the wind to eastward of South, very heavy clouds to the North & N. West with much Lightning, the wind suddenly veer'd about to N. W. when the atmosphere for an Hour or more was almost a continued Blaze of Light but no very heavy Thunder, for a considerable Time it rained heavilly; 80. i°; Idem. 770; Overcast, rain 75.30; Thick, rain, thunder storm & blew violently from N. W. about 10 minutes September is Cool and Pleasant Wind N. W. & Weather cool & pleasant 64.7°; Overcast, windy September i6 Cool & Pleasant pleasant weather 51.8°; Clouds, fair, but cold September 17 Clear & Quite Cool cool 48.8°; lowest temperature of September, 36.5°; Fair, cold, overcast