TABLE 1.

Mean absolute percentage errors (MAPEs) of the forecasts of the epidemic evolution in Lombardia, Italy, performed at different dates and calculated for different forecast horizons, that is, 3, 7, and 14 days. The asterisk means that the forecast performed at a given date and with a given forecast horizon includes May 6, when inaccurate numbers of infected and recovered individuals were reported. The average (last row) does not take into account these cases.

Forecast Date	3 Days (%)	7 Days (%)	14 Days (%)
April 13	0.54	0.50	2.49
April 18	3.47	6.48	6.84
April 23	1.25	1.91	3.88*
April 28	0.42	1.07	14.91*
May 3	8.02*	18.44*	30.07*
May 8	9.14	7.47	6.31
May 13	2.30	2.59	6.48
May 18	0.92	2.24	3.29
May 23	0.69	3.78	9.02
May 28	4.67	5.10	4.99
June 2	2.70	1.87	1.93
June 7	4.02	6.61	10.76
Average	2.74	3.60	5.79