Historical data for weatherstation Volkel (🇳🇱) KNMI

Historical data for July 21, 2023

Daily summary for: July 21, 2023

Max. Temperature 21.7 °C (12:50 p.m.)
Min. Temperature 9.0 °C (5:40 a.m.)
Max. Windspeed 49.1 km/h (1:50 p.m.)
Total Precipitation 2.9 mm

Graphs

Temperature on July 21, 2023

Windspeed on July 21, 2023

Pressure on July 21, 2023

Humidity on July 21, 2023

Solarradiation on July 21, 2023

Precipitation on July 21, 2023

Precipitation rate on July 21, 2023

All observations

Time Temperature Dewpoint Humidity Windspeed Winddirection Precipitation Precipitation rate Pressure Solarradiation UV
midnight 12.6 °C 12.5 °C 99 % 4.4 km/h N 0.1 mm 0.0 mm/h 1013.3 hPa 0.0 w/m^2
12:10 a.m. 12.9 °C 12.8 °C 99 % 3.5 km/h NW 0.0 mm 0.0 mm/h 1013.3 hPa 0.0 w/m^2
12:20 a.m. 13.0 °C 12.9 °C 99 % 1.5 km/h W 0.0 mm 0.0 mm/h 1013.2 hPa 0.0 w/m^2
12:30 a.m. 12.8 °C 12.5 °C 98 % 0.4 km/h W 0.0 mm 0.0 mm/h 1013.2 hPa 0.0 w/m^2
12:40 a.m. 12.6 °C 12.2 °C 97 % 0.0 km/h W 0.0 mm 0.0 mm/h 1013.2 hPa 0.0 w/m^2
12:50 a.m. 12.4 °C 12.4 °C 99 % 0.0 km/h W 0.0 mm 0.0 mm/h 1013.1 hPa 0.0 w/m^2
1 a.m. 12.6 °C 12.4 °C 98 % 1.7 km/h W 0.0 mm 0.0 mm/h 1013.1 hPa 0.0 w/m^2
1:10 a.m. 12.3 °C 12.2 °C 99 % 3.0 km/h W 0.0 mm 0.0 mm/h 1013.1 hPa 0.0 w/m^2
1:20 a.m. 12.1 °C 12.0 °C 99 % 2.5 km/h W 0.0 mm 0.0 mm/h 1013.1 hPa 0.0 w/m^2
1:30 a.m. 11.6 °C 11.5 °C 99 % 2.7 km/h W 0.0 mm 0.0 mm/h 1013.0 hPa 0.0 w/m^2
1:40 a.m. 12.1 °C 12.1 °C 99 % 2.3 km/h W 0.0 mm 0.0 mm/h 1013.0 hPa 0.0 w/m^2
1:50 a.m. 11.6 °C 11.5 °C 99 % 2.9 km/h W 0.0 mm 0.0 mm/h 1012.9 hPa 0.0 w/m^2
2 a.m. 11.2 °C 11.1 °C 99 % 4.6 km/h W 0.0 mm 0.0 mm/h 1012.8 hPa 0.0 w/m^2
2:10 a.m. 11.5 °C 11.3 °C 99 % 6.2 km/h SW 0.0 mm 0.0 mm/h 1012.8 hPa 0.0 w/m^2
2:20 a.m. 11.8 °C 11.7 °C 99 % 6.4 km/h SW 0.0 mm 0.0 mm/h 1012.8 hPa 0.0 w/m^2
2:30 a.m. 11.7 °C 11.7 °C 99 % 4.0 km/h SW 0.0 mm 0.0 mm/h 1012.8 hPa 0.0 w/m^2
2:40 a.m. 11.9 °C 11.9 °C 99 % 3.1 km/h SW 0.0 mm 0.0 mm/h 1012.7 hPa 0.0 w/m^2
2:50 a.m. 11.4 °C 11.2 °C 98 % 3.8 km/h SW 0.0 mm 0.0 mm/h 1012.6 hPa 0.0 w/m^2
3 a.m. 11.3 °C 11.1 °C 98 % 2.1 km/h SW 0.0 mm 0.0 mm/h 1012.6 hPa 0.0 w/m^2
3:10 a.m. 11.6 °C 11.5 °C 99 % 2.2 km/h SW 0.0 mm 0.0 mm/h 1012.5 hPa 0.0 w/m^2
3:20 a.m. 11.6 °C 11.6 °C 99 % 3.0 km/h SW 0.0 mm 0.0 mm/h 1012.4 hPa 0.0 w/m^2
3:30 a.m. 11.6 °C 11.5 °C 99 % 3.7 km/h SW 0.0 mm 0.0 mm/h 1012.3 hPa 0.0 w/m^2
3:40 a.m. 11.1 °C 11.0 °C 99 % 3.8 km/h W 0.0 mm 0.0 mm/h 1012.2 hPa 0.0 w/m^2
3:50 a.m. 10.7 °C 10.5 °C 98 % 2.4 km/h W 0.0 mm 0.0 mm/h 1012.1 hPa 0.0 w/m^2
4 a.m. 10.6 °C 10.5 °C 99 % 0.0 km/h W 0.0 mm 0.0 mm/h 1012.1 hPa 0.0 w/m^2
4:10 a.m. 10.7 °C 10.6 °C 99 % 1.2 km/h W 0.0 mm 0.0 mm/h 1012.0 hPa 0.0 w/m^2
4:20 a.m. 10.5 °C 10.5 °C 99 % 1.6 km/h W 0.0 mm 0.0 mm/h 1012.0 hPa 0.0 w/m^2
4:30 a.m. 10.2 °C 10.1 °C 99 % 2.3 km/h W 0.0 mm 0.0 mm/h 1011.9 hPa 0.0 w/m^2
4:40 a.m. 10.2 °C 10.0 °C 98 % 4.2 km/h W 0.0 mm 0.0 mm/h 1011.9 hPa 0.0 w/m^2
4:50 a.m. 10.5 °C 10.4 °C 99 % 3.8 km/h SW 0.0 mm 0.0 mm/h 1011.9 hPa 0.0 w/m^2
5 a.m. 11.0 °C 10.9 °C 99 % 3.6 km/h W 0.0 mm 0.0 mm/h 1011.8 hPa 0.0 w/m^2
5:10 a.m. 10.1 °C 10.0 °C 99 % 2.0 km/h W 0.0 mm 0.0 mm/h 1011.8 hPa 0.0 w/m^2
5:20 a.m. 9.8 °C 9.6 °C 98 % 0.0 km/h W 0.0 mm 0.0 mm/h 1011.7 hPa 0.0 w/m^2
5:30 a.m. 10.0 °C 9.8 °C 98 % 3.3 km/h W 0.0 mm 0.0 mm/h 1011.8 hPa 0.0 w/m^2
5:40 a.m. 9.0 °C 8.8 °C 98 % 4.6 km/h SW 0.0 mm 0.0 mm/h 1011.8 hPa 0.0 w/m^2
5:50 a.m. 9.6 °C 9.4 °C 99 % 4.6 km/h SW 0.0 mm 0.0 mm/h 1011.7 hPa 2.0 w/m^2
6 a.m. 9.9 °C 9.9 °C 99 % 4.8 km/h SW 0.0 mm 0.0 mm/h 1011.7 hPa 8.0 w/m^2
6:10 a.m. 9.4 °C 9.1 °C 98 % 5.7 km/h SW 0.0 mm 0.0 mm/h 1011.7 hPa 13.0 w/m^2
6:20 a.m. 9.4 °C 9.2 °C 98 % 7.7 km/h SW 0.0 mm 0.0 mm/h 1011.6 hPa 22.0 w/m^2
6:30 a.m. 9.3 °C 9.2 °C 99 % 7.6 km/h SW 0.0 mm 0.0 mm/h 1011.6 hPa 39.0 w/m^2
6:40 a.m. 9.9 °C 9.8 °C 98 % 7.8 km/h SW 0.0 mm 0.0 mm/h 1011.6 hPa 53.0 w/m^2
6:50 a.m. 10.6 °C 10.6 °C 99 % 5.7 km/h SW 0.0 mm 0.0 mm/h 1011.5 hPa 78.0 w/m^2
7 a.m. 11.2 °C 11.2 °C 99 % 4.3 km/h SW 0.0 mm 0.0 mm/h 1011.4 hPa 113.0 w/m^2
7:10 a.m. 11.8 °C 11.7 °C 98 % 3.9 km/h SW 0.0 mm 0.0 mm/h 1011.5 hPa 143.0 w/m^2
7:20 a.m. 12.4 °C 12.1 °C 98 % 5.1 km/h SW 0.0 mm 0.0 mm/h 1011.5 hPa 170.0 w/m^2
7:30 a.m. 12.6 °C 12.3 °C 98 % 5.3 km/h SW 0.0 mm 0.0 mm/h 1011.5 hPa 136.0 w/m^2
7:40 a.m. 13.0 °C 12.6 °C 97 % 5.9 km/h SW 0.0 mm 0.0 mm/h 1011.5 hPa 178.0 w/m^2
7:50 a.m. 13.4 °C 13.0 °C 97 % 5.8 km/h SW 0.0 mm 0.0 mm/h 1011.5 hPa 212.0 w/m^2
8 a.m. 13.9 °C 13.2 °C 95 % 6.5 km/h W 0.0 mm 0.0 mm/h 1011.6 hPa 225.0 w/m^2
8:10 a.m. 14.5 °C 13.5 °C 93 % 6.9 km/h NW 0.0 mm 0.0 mm/h 1011.5 hPa 246.0 w/m^2
8:20 a.m. 14.7 °C 13.7 °C 93 % 7.3 km/h NW 0.0 mm 0.0 mm/h 1011.5 hPa 272.0 w/m^2
8:30 a.m. 15.3 °C 14.3 °C 93 % 7.8 km/h NW 0.0 mm 0.0 mm/h 1011.5 hPa 330.0 w/m^2
8:40 a.m. 15.9 °C 14.1 °C 89 % 5.3 km/h NW 0.0 mm 0.0 mm/h 1011.6 hPa 382.0 w/m^2
8:50 a.m. 16.2 °C 14.0 °C 87 % 5.1 km/h W 0.0 mm 0.0 mm/h 1011.5 hPa 309.0 w/m^2
9 a.m. 16.6 °C 14.3 °C 86 % 5.7 km/h W 0.0 mm 0.0 mm/h 1011.4 hPa 301.0 w/m^2
9:10 a.m. 17.0 °C 13.8 °C 81 % 9.3 km/h SW 0.0 mm 0.0 mm/h 1011.4 hPa 295.0 w/m^2
9:20 a.m. 16.9 °C 13.7 °C 81 % 8.5 km/h SW 0.0 mm 0.0 mm/h 1011.4 hPa 254.0 w/m^2
9:30 a.m. 17.3 °C 14.0 °C 81 % 7.7 km/h SW 0.0 mm 0.0 mm/h 1011.4 hPa 253.0 w/m^2
9:40 a.m. 17.4 °C 13.4 °C 77 % 8.9 km/h SW 0.0 mm 0.0 mm/h 1011.4 hPa 263.0 w/m^2
9:50 a.m. 17.7 °C 13.9 °C 78 % 9.2 km/h SW 0.0 mm 0.0 mm/h 1011.5 hPa 324.0 w/m^2
10 a.m. 17.7 °C 13.4 °C 75 % 9.5 km/h SW 0.0 mm 0.0 mm/h 1011.4 hPa 382.0 w/m^2
10:10 a.m. 18.2 °C 13.6 °C 74 % 10.4 km/h SW 0.0 mm 0.0 mm/h 1011.4 hPa 413.0 w/m^2
10:20 a.m. 18.2 °C 12.6 °C 69 % 11.0 km/h W 0.0 mm 0.0 mm/h 1011.4 hPa 410.0 w/m^2
10:30 a.m. 18.3 °C 12.4 °C 68 % 11.8 km/h W 0.0 mm 0.0 mm/h 1011.4 hPa 343.0 w/m^2
10:40 a.m. 18.6 °C 12.8 °C 69 % 11.1 km/h SW 0.0 mm 0.0 mm/h 1011.4 hPa 435.0 w/m^2
10:50 a.m. 18.6 °C 12.0 °C 65 % 12.7 km/h SW 0.0 mm 0.0 mm/h 1011.4 hPa 423.0 w/m^2
11 a.m. 18.9 °C 11.9 °C 63 % 13.4 km/h SW 0.0 mm 0.0 mm/h 1011.4 hPa 409.0 w/m^2
11:10 a.m. 19.3 °C 11.7 °C 61 % 13.1 km/h W 0.0 mm 0.0 mm/h 1011.4 hPa 486.0 w/m^2
11:20 a.m. 18.9 °C 10.3 °C 57 % 13.3 km/h W 0.0 mm 0.0 mm/h 1011.4 hPa 311.0 w/m^2
11:30 a.m. 19.3 °C 11.3 °C 59 % 17.0 km/h W 0.0 mm 0.0 mm/h 1011.4 hPa 457.0 w/m^2
11:40 a.m. 19.7 °C 10.9 °C 56 % 17.0 km/h W 0.0 mm 0.0 mm/h 1011.3 hPa 604.0 w/m^2
11:50 a.m. 20.4 °C 11.2 °C 55 % 16.7 km/h SW 0.0 mm 0.0 mm/h 1011.3 hPa 695.0 w/m^2
noon 20.5 °C 10.4 °C 52 % 22.1 km/h SW 0.0 mm 0.0 mm/h 1011.2 hPa 765.0 w/m^2
12:10 p.m. 21.1 °C 10.4 °C 50 % 19.8 km/h W 0.0 mm 0.0 mm/h 1011.0 hPa 910.0 w/m^2
12:20 p.m. 20.4 °C 10.4 °C 52 % 23.2 km/h W 0.0 mm 0.0 mm/h 1011.0 hPa 821.0 w/m^2
12:30 p.m. 20.4 °C 10.5 °C 53 % 19.4 km/h W 0.0 mm 0.0 mm/h 1011.0 hPa 393.0 w/m^2
12:40 p.m. 20.6 °C 11.0 °C 54 % 20.8 km/h W 0.0 mm 0.0 mm/h 1011.0 hPa 521.0 w/m^2
12:50 p.m. 21.7 °C 11.5 °C 52 % 22.9 km/h W 0.0 mm 0.0 mm/h 1011.0 hPa 944.0 w/m^2
1 p.m. 20.6 °C 10.9 °C 53 % 25.3 km/h W 0.0 mm 0.0 mm/h 1011.0 hPa 731.0 w/m^2
1:10 p.m. 20.4 °C 10.5 °C 53 % 18.6 km/h W 0.0 mm 0.0 mm/h 1011.0 hPa 349.0 w/m^2
1:20 p.m. 20.2 °C 10.4 °C 53 % 20.2 km/h SW 0.0 mm 0.0 mm/h 1011.0 hPa 294.0 w/m^2
1:30 p.m. 19.8 °C 10.9 °C 56 % 19.0 km/h SW 0.0 mm 0.0 mm/h 1011.1 hPa 165.0 w/m^2
1:40 p.m. 19.3 °C 11.4 °C 60 % 24.1 km/h SW 0.0 mm 0.0 mm/h 1011.3 hPa 96.0 w/m^2
1:50 p.m. 14.4 °C 12.1 °C 86 % 49.1 km/h W 0.1 mm 0.8 mm/h 1011.8 hPa 29.0 w/m^2
2 p.m. 14.0 °C 12.6 °C 91 % 29.5 km/h W 1.7 mm 9.4 mm/h 1011.9 hPa 41.0 w/m^2
2:10 p.m. 14.4 °C 12.8 °C 90 % 24.4 km/h W 2.1 mm 2.4 mm/h 1011.8 hPa 88.0 w/m^2
2:20 p.m. 15.0 °C 13.4 °C 90 % 12.7 km/h W 2.4 mm 1.9 mm/h 1011.6 hPa 196.0 w/m^2
2:30 p.m. 16.0 °C 13.7 °C 86 % 7.6 km/h W 2.4 mm 0.1 mm/h 1011.5 hPa 313.0 w/m^2
2:40 p.m. 16.7 °C 12.8 °C 77 % 10.1 km/h W 2.4 mm 0.0 mm/h 1011.5 hPa 290.0 w/m^2
2:50 p.m. 16.4 °C 13.1 °C 80 % 22.0 km/h SW 2.4 mm 0.0 mm/h 1011.8 hPa 135.0 w/m^2
3 p.m. 15.3 °C 13.6 °C 89 % 26.8 km/h W 2.6 mm 0.8 mm/h 1011.9 hPa 86.0 w/m^2
3:10 p.m. 15.4 °C 13.8 °C 90 % 24.2 km/h SW 2.8 mm 1.6 mm/h 1011.9 hPa 128.0 w/m^2
3:20 p.m. 15.5 °C 13.2 °C 86 % 18.5 km/h SW 2.9 mm 0.7 mm/h 1011.8 hPa 128.0 w/m^2
3:30 p.m. 15.6 °C 13.4 °C 86 % 14.0 km/h SW 2.9 mm 0.0 mm/h 1011.7 hPa 104.0 w/m^2
3:40 p.m. 16.4 °C 14.8 °C 90 % 11.6 km/h SW 2.9 mm 0.0 mm/h 1011.7 hPa 195.0 w/m^2
3:50 p.m. 17.0 °C 13.9 °C 81 % 14.9 km/h SW 2.9 mm 0.0 mm/h 1011.7 hPa 349.0 w/m^2
4 p.m. 16.7 °C 13.4 °C 81 % 16.5 km/h SW 2.9 mm 0.0 mm/h 1011.8 hPa 125.0 w/m^2
4:10 p.m. 16.8 °C 14.1 °C 84 % 13.4 km/h SW 2.9 mm 0.0 mm/h 1011.9 hPa 117.0 w/m^2
4:20 p.m. 16.9 °C 13.7 °C 81 % 12.6 km/h W 2.9 mm 0.0 mm/h 1011.8 hPa 111.0 w/m^2
4:30 p.m. 17.2 °C 14.2 °C 82 % 13.6 km/h SW 2.9 mm 0.0 mm/h 1011.9 hPa 145.0 w/m^2
4:40 p.m. 17.4 °C 14.6 °C 83 % 13.9 km/h SW 2.9 mm 0.0 mm/h 1011.9 hPa 132.0 w/m^2
4:50 p.m. 18.0 °C 14.4 °C 79 % 12.8 km/h SW 2.9 mm 0.0 mm/h 1012.0 hPa 273.0 w/m^2
5 p.m. 18.9 °C 13.9 °C 72 % 15.0 km/h W 2.9 mm 0.0 mm/h 1011.8 hPa 499.0 w/m^2
5:10 p.m. 19.1 °C 13.7 °C 70 % 15.5 km/h W 2.9 mm 0.0 mm/h 1011.8 hPa 533.0 w/m^2
5:20 p.m. 18.5 °C 13.1 °C 70 % 16.6 km/h W 2.9 mm 0.0 mm/h 1011.8 hPa 191.0 w/m^2
5:30 p.m. 18.8 °C 13.1 °C 69 % 12.8 km/h W 2.9 mm 0.0 mm/h 1011.8 hPa 325.0 w/m^2
5:40 p.m. 18.8 °C 13.4 °C 70 % 15.3 km/h W 2.9 mm 0.0 mm/h 1011.9 hPa 231.0 w/m^2
5:50 p.m. 19.3 °C 11.8 °C 61 % 21.8 km/h W 2.9 mm 0.0 mm/h 1012.0 hPa 453.0 w/m^2
6 p.m. 19.7 °C 11.2 °C 58 % 25.8 km/h W 2.9 mm 0.0 mm/h 1012.0 hPa 547.0 w/m^2
6:10 p.m. 19.8 °C 9.5 °C 51 % 23.4 km/h W 2.9 mm 0.0 mm/h 1012.1 hPa 479.0 w/m^2
6:20 p.m. 19.4 °C 10.1 °C 54 % 22.7 km/h W 2.9 mm 0.0 mm/h 1012.2 hPa 387.0 w/m^2
6:30 p.m. 19.5 °C 8.1 °C 47 % 25.3 km/h W 2.9 mm 0.0 mm/h 1012.2 hPa 401.0 w/m^2
6:40 p.m. 19.8 °C 7.5 °C 44 % 24.3 km/h W 2.9 mm 0.0 mm/h 1012.2 hPa 393.0 w/m^2
6:50 p.m. 19.7 °C 8.7 °C 49 % 31.4 km/h W 2.9 mm 0.0 mm/h 1012.3 hPa 375.0 w/m^2
7 p.m. 19.4 °C 9.0 °C 51 % 28.9 km/h W 2.9 mm 0.0 mm/h 1012.4 hPa 346.0 w/m^2
7:10 p.m. 19.0 °C 8.6 °C 50 % 27.1 km/h W 2.9 mm 0.0 mm/h 1012.5 hPa 310.0 w/m^2
7:20 p.m. 18.8 °C 8.7 °C 51 % 26.6 km/h W 2.9 mm 0.0 mm/h 1012.6 hPa 267.0 w/m^2
7:30 p.m. 18.8 °C 8.8 °C 52 % 30.2 km/h W 2.9 mm 0.0 mm/h 1012.8 hPa 250.0 w/m^2
7:40 p.m. 18.5 °C 7.6 °C 48 % 28.9 km/h W 2.9 mm 0.0 mm/h 1012.8 hPa 232.0 w/m^2
7:50 p.m. 18.5 °C 7.7 °C 49 % 28.9 km/h W 2.9 mm 0.0 mm/h 1012.9 hPa 209.0 w/m^2
8 p.m. 18.3 °C 7.7 °C 50 % 27.7 km/h W 2.9 mm 0.0 mm/h 1012.9 hPa 180.0 w/m^2
8:10 p.m. 18.1 °C 8.1 °C 52 % 21.1 km/h W 2.9 mm 0.0 mm/h 1013.0 hPa 154.0 w/m^2
8:20 p.m. 17.9 °C 8.7 °C 54 % 19.7 km/h W 2.9 mm 0.0 mm/h 1013.0 hPa 125.0 w/m^2
8:30 p.m. 17.7 °C 9.1 °C 57 % 20.4 km/h W 2.9 mm 0.0 mm/h 1013.1 hPa 103.0 w/m^2
8:40 p.m. 17.1 °C 9.3 °C 60 % 14.3 km/h W 2.9 mm 0.0 mm/h 1013.1 hPa 45.0 w/m^2
8:50 p.m. 16.9 °C 9.2 °C 60 % 17.4 km/h NW 2.9 mm 0.0 mm/h 1013.2 hPa 27.0 w/m^2
9 p.m. 16.8 °C 9.2 °C 61 % 12.9 km/h W 2.9 mm 0.0 mm/h 1013.3 hPa 31.0 w/m^2
9:10 p.m. 16.7 °C 9.4 °C 62 % 14.3 km/h W 2.9 mm 0.0 mm/h 1013.4 hPa 21.0 w/m^2
9:20 p.m. 16.5 °C 9.6 °C 63 % 8.9 km/h W 2.9 mm 0.0 mm/h 1013.5 hPa 14.0 w/m^2
9:30 p.m. 16.3 °C 9.7 °C 65 % 8.3 km/h W 2.9 mm 0.0 mm/h 1013.6 hPa 7.0 w/m^2
9:40 p.m. 16.1 °C 9.8 °C 66 % 7.6 km/h W 2.9 mm 0.0 mm/h 1013.7 hPa 2.0 w/m^2
9:50 p.m. 15.8 °C 9.8 °C 67 % 7.3 km/h W 2.9 mm 0.0 mm/h 1013.9 hPa 0.0 w/m^2
10 p.m. 15.7 °C 9.8 °C 67 % 7.8 km/h W 2.9 mm 0.0 mm/h 1014.0 hPa 0.0 w/m^2
10:10 p.m. 15.9 °C 9.7 °C 66 % 11.3 km/h W 2.9 mm 0.0 mm/h 1014.1 hPa 0.0 w/m^2
10:20 p.m. 15.8 °C 9.9 °C 68 % 11.0 km/h W 2.9 mm 0.0 mm/h 1014.1 hPa 0.0 w/m^2
10:40 p.m. 15.8 °C 10.4 °C 70 % 11.6 km/h W 2.9 mm 0.0 mm/h 1014.2 hPa 0.0 w/m^2
10:50 p.m. 15.8 °C 10.6 °C 71 % 10.4 km/h W 2.9 mm 0.0 mm/h 1014.3 hPa 0.0 w/m^2
11 p.m. 15.6 °C 10.7 °C 72 % 9.3 km/h W 2.9 mm 0.0 mm/h 1014.3 hPa 0.0 w/m^2
11:10 p.m. 15.4 °C 10.8 °C 74 % 9.4 km/h W 2.9 mm 0.0 mm/h 1014.4 hPa 0.0 w/m^2
11:20 p.m. 15.2 °C 10.9 °C 75 % 4.8 km/h W 2.9 mm 0.0 mm/h 1014.3 hPa 0.0 w/m^2