Table 1.
Details of 3,913 0.25° grid cell-weeks of observation for COVID-19 incident cases in China (excluding Wuhan City) during January–February 2020, covering a total of 18,069 cases among a population of 151.2 million. All grid cells in which at least one case was observed during the overall period of observation are included. Bivariate incidence rate ratios and their 95% confidence intervals were calculated using a Poisson regression model with the weekly number of cases as the dependent variable, the grid cell population as the exposure variable and the previous week’s weather data as independent variables
| Parameter | Level | Units | Range | Median | Bivariate incidence rate ratio | 95% confidence interval |
|---|---|---|---|---|---|---|
| Latitude | degrees | 18.25 to 49.75 | 32.25 | |||
| Longitude | degrees | 82.00 to 132.25 | 113.25 | |||
| Population | per grid cell | n | 1,169 to 2.56 million |
187,616 | ||
| COVID-19 cases | per grid cell | n | 1 to 1,262 | 6 | ||
| Week in 2020 | 3 | 1 (ref) | – | |||
| 4 | 27.5 | 22.7–33.4 | ||||
| 5 | 84.9 | 70.2–102.7 | ||||
| 6 | 38.9 | 32.1–47.0 | ||||
| 7 | 11.8 | 9.7–14.4 | ||||
| 8 | 1.80 | 1.4–2.3 | ||||
| 9 | 1.38 | 1.1–1.8 | ||||
| Population density | 1st quintile | km−2 | 2 to 109 | 57 | 1 (ref) | – |
| 2nd quintile | km−2 | 110 to 198 | 155 | 0.75 | 0.69–0.81 | |
| 3rd quintile | km−2 | 199 to 392 | 275 | 1.01 | 0.94–1.08 | |
| 4th quintile | km−2 | 393 to 631 | 489 | 0.67 | 0.63–0.72 | |
| 5th quintile | km−2 | 632 to 3,626 | 788 | 0.20 | 0.18–0.21 | |
| Preceding week mean of daily maximum temperature | 1st tertile | °C | −18.1 to 5.2 | −0.3 | 1 (ref) | – |
| 2nd tertile | °C | 5.2 to 11.7 | 8.5 | 2.11 | 2.02–2.20 | |
| 3rd tertile | °C | 11.7 to 29.2 | 16.1 | 1.00 | 0.96–1.05 | |
| Preceding week mean of daily minimum temperature | 1st tertile | °C | −31.2 to −3.1 | −11.3 | 1 (ref) | – |
| 2nd tertile | °C | −3.1 to 4.5 | 1.4 | 3.27 | 3.11–3.42 | |
| 3rd tertile | °C | 4.5 to 15.9 | 8.3 | 1.13 | 1.07–1.19 | |
| Preceding week mean of daily average temperature | 1st tertile | °C | −22.4 to 1.2 | −5.7 | 1 (ref) | – |
| 2nd tertile | °C | 1.2 to 8.1 | 4.8 | 3.58 | 3.42–3.76 | |
| 3rd tertile | °C | 8.1 to 19.4 | 12.0 | 1.11 | 1.05–1.17 | |
| Preceding week mean of daily max solar surface radiation | 1st tertile | MJm−2 | 0.07 to 0.82 | 0.59 | 1 (ref) | – |
| 2nd tertile | MJm−2 | 0.59 to 1.33 | 1.07 | 2.57 | 2.48–2.67 | |
| 3rd tertile | MJm−2 | 1.33 to 2.44 | 1.64 | 0.72 | 0.69–0.76 | |
| Preceding week total precipitation | 1st tertile | mm | 0 to 4.1 | 1.8 | 1 (ref) | – |
| 2nd tertile | mm | 4.1 to 11.4 | 7.2 | 2.57 | 2.44–2.70 | |
| 3rd tertile | mm | 11.4 to 55.9 | 17.2 | 4.71 | 4.50–4.94 |