Table 1.
Average value of different source variables for different time periods.a
| Variables | 2012-2013 | 2013-2014 | 2014-2015 | 2015-2016 | 2016-2017 | 2017-2018 | 2018-2019 |
| ILIb cases, n | 13,748 | 12,300 | 12,351 | 13,887 | 14,318 | 19,100 | 21,142 |
| Influenza-positive cases, n | 26.00 | 37.00 | 47.00 | 39.00 | 30.00 | 45.00 | 45.00 |
| Maximum temperature (℃) | 16.32 | 18.55 | 18.42 | 18.20 | 18.64 | 17.97 | 18.35 |
| Minimum temperature (℃) | 5.45 | 6.93 | 6.58 | 6.85 | 7.06 | 6.32 | 6.17 |
| Temperature difference (℃) | 10.87 | 11.62 | 11.84 | 11.35 | 11.58 | 11.65 | 12.17 |
| Mean temperature (℃) | 10.53 | 12.29 | 12.12 | 12.22 | 12.46 | 11.77 | 11.90 |
| Relative humidity (g/m3) | 58.48 | 50.05 | 50.83 | 54.94 | 55.47 | 53.73 | 51.30 |
| Atmosphere pressure (hPa) | 993.18 | 992.97 | 993.46 | 993.75 | 993.77 | 993.48 | 994.01 |
| Wind speed (m/s) | 1.85 | 90.17 | 1.76 | 1.77 | 1.66 | 1.69 | 1.70 |
| Precipitation (cm) | 1.67 | 1.66 | 1.22 | 1.54 | 1.56 | 1.38 | 1.27 |
| Sunlight (weeks) | 6.51 | 6.67 | 6.63 | 6.52 | 6.67 | 6.97 | 7.02 |
| AQIc | 70.19 | 64.42 | 70.19 | 100.38 | 159.13 | 108.65 | 115.38 |
| Baidu search index for “influenza” | 117.00 | 205.00 | 218.00 | 215.00 | 284.00 | 428.00 | 443.00 |
aIn each time period, data were collected from the 26th week of the first year to the 25th week of the subsequent year.
bILI: influenza-like illness.
cAQI: air quality index.