Table 1.

Descriptive statistics of daily air pollutants and meteorological variables in 232 Chinese cities, from Jan. 1st, 2020 to Apr. 6th, 2020.

Variables	Air pollutants and meteorology
	Mean	SD	Min	P25	Median	P75	Max
AQI	61.55	42.82	9.08	35.08	52.33	73.83	500.00
Pollutants
CO (mg/m3)	0.74	0.34	0.10	0.54	0.68	0.86	4.08
NO2 (μg/m3)	20.77	11.86	1.46	11.79	18.33	27.17	85.32
O3 (μg/m3)	59.33	19.50	3.88	35.73	59.38	72.29	153.39
PM2.5 (μg/m3)	38.45	34.78	1.29	18.72	30.75	47.63	1188.58
PM10 (μg/m3)	64.24	78.32	3.26	31.33	50.09	77.42	2767.83
SO2 (μg/m3)	10.21	6.99	1.14	5.79	8.17	12.29	94.00
Meteorology
Temperature (°C)	7.59	8.58	−32.69	2.33	8.35	13.49	31.00
Dew point temperature (°C)	−0.27	10.85	−48.75	−8.65	0.79	7.87	24.05
Wind speed (m/s)	2.59	1.40	0.00	1.64	2.28	3.19	15.14

Note: SD, standard deviation.