Table 1 Incidence rate ratios for COVID-19 derived from negative binomial regression showing both unadjusted and multivariable-adjusted analyses from March 16th–December 31st, 2020

Variable

IRR [95% C.I.]

aIRR [95% C.I.]

Wind speed (Ln–KPH) when temperature 16–28 °C

1.85 [1.67–2.06]

P < 0.001

1.17 [1.09–1.26]

P < 0.001

Wind speed (Ln–KPH) when temperature ≤ 15 or ≥ 29 °C

1.04 [0.79–1.36]

P = 0.798

0.93 [0.81–1.06]

P = 0.248

Maximal exterior temperature, °C

1.00 [0.99–1.01]

P = 0.677

Days since lockdown

0.95 [0.93–0.97]

P < 0.001

Days since reopening

1.06 [1.04–1.08]

P < 0.001

Holiday adjustment

1.11 [0.92–1.33]

P = 0.264

Snowfall, cm

0.98 [0.92–1.04]

P = 0.540

Rainfall, cm

1.01 [0.94–1.09]

1.02 P = 0.776

Eight-day forward/backward moving average

1.22 [1.20–1.25]

P < 0.001

α

0.98 [0.85–1.13]

0.17 [0.14–0.2]