The Climate of Peoria. 37 
=39.5. The highest stand of the thermometer was observed in March 1860 on 
the 30th =79; in April 1856 on the 26th =88.5; in May 1860 on the 24th =98.5; 
the lowest in March 1867 on the 14th —6; in April 1857 on the 15th =18; in 
May 1867 on the 8th =30. 
There are in average 18 frost days in March, 5 in April, and in May 5 were 
were observed in 30 years. The most frost days had the March in 1859 =29, 
and April in 1857 =18, There was no frost day observed in April 1878; only 
13 per cent. of the frost days of April occurred after the 17th, at which date 
for the last time a mean temperature below freezing point was observed. 
SUMMER. 
The mean temperature of the three summer months is 75.5. The coolest 
summer was in 1866 and 1869 =73; the warmest in 1874 =79. The coolest 
June in 1869 =69; the coolest July 1865 —71; the coolest August 1866 =70; 
the warmest June in 1873 =79; the warmest July 1868 =82.7; the warmest 
August 1881 =80.5. The mean temperature of the decades was, of June, 1st 
decade =70, 2d =73, 3d =77; of July lst =77.9, 2d =78.3, 8d =77.2; of August 
Ist =77, 2d =756, 3d =73.3. The coolest decade of June was the ist of 1863 
=63, of July the 2d in 1865 =65.3, of August the 3d in 1863 =—65.3; the warm- 
est in June the 3d in 1858 =85, in July the 2d in 1878 =89.8, in August the 
1st in 1861 =86.7. 
Of the single observations was the highest for June on the 24th, in 1856 
=100; for July on the 15th, 1859, on the 4th, 1874, and on the 30th, 1885=104; 
for August on the 31st in 1873 =105; the lowest for June on the 4th, 1859, 
=35; for July on the 2d in 1861 and the 16th in 1863 =50; for August on the 
~ 29th in 1863 =41. 
FALL. 
The mean temperature of the three fall months is 53.3. The coolest fall was 
in 1880 =48.9; the warmest in 1884 =658.1; the coolest September was in 1866 
=60.5; the warmest in 1865 =73.1; the coolest October in 1869 =48.2; the 
warmest in 1879 =62.7; the coolest November in 1880 =30,3; the warmest in 
1867 =44.4. The mean temperature of the decades are the following for Sep- 
tember: lst =70.8, 2d =66°4, 3d =63; for October 1st =59.7, 2d =53.5, 3d 
=48.5; for November Ist =45.5, 2d =38.8, 3d =33.9. The coolest decade in 
September was the 3d in 1856 =—52.7; the warmest the lst in 1884 =81.3; 
the coolest in October the 3d in 1869 =36.3; the warmest the lst in 1879=76.3; 
the coolest in November the 3d in 1880 =20.3; the warmest the lst in 1874 
=64.5. The highest stand of the thermometer was observed on the 3d of Sep- 
tember 1864, and 5th of September 1881 —98, on the 3d of October 1856, 12th 
of October 1879 and 8th of October 1884 =—90; on the 7th of November 1874 
=77; the lowest on the 29th of September 1871 =384; on the 24th of October 
1869 =14; and 23d of November 1857,=—1.5. 
By comparison of the temperature of different places in Illinois during the 
meteorological year December 1869 to November 1870 we find in the mean 
temperatures of Peoria, Springfield, which is nearly a degree farther south, 
and Ottawa which is more than half a degree farther north, scarcely any differ- 
ence, but Galesburg, farther west and on a higher elevation, had that same year 
a mean of one degree lower and a January very much colder. Of the same 
year the temperatures of Steubenville, O., Fort Madison on the Mississippi 
and Nebraska City on the Missouri, all nearly in the same latitude with 
Peoria, compared show the following figures: 
Mean of the year. In winter. In summer. 
Steubenville .............. DAD... coum. 00+ cake Oh easy 03 hth ss sos ae 75.2 
GONE Tih edoe ss <a astra cass Cy ea REPAY ccs tet: «Ss caen tak 76.6 
Ft. Madison .....+..Jsc000s DB.O «cgeeeha ss... oda BENDS th’ e'daen's snisaviwenee? 76.6 
Nebraska City ........... Ny eee BM Oita ib sds ¥e aR, oes 74.8 
