A weather file will consist of a group of parameters relating to the weather site and hourly values of 7 weather variables, from global radiation, humidity, to wind speed and cloud cover.
SITE PARAMETERS:
Parameters |
Details |
Weather File |
The name of the weather site. |
Description |
Comments of the weather site. |
Latitude (degrees North) |
The latitude of the weather site. |
Longitude (degrees E) |
The longitude of the weather site. |
Altitude (m) |
The height the weather site is above sea level. |
Time Zone (hours ahead of GMT) |
The time zone of the weather site (in the range –13 hours to +13 hours). Note: the Longitude and Time Zone parameters indicate the location of the solar radiation measurements and the time convention used to record them; editing these parameters is NOT a valid way to allow for seasonal time adjustments such as British Summer Time. |
Year (A.D.) |
The year the weather data was measured from. |
Ground Temperature (deg. C) |
The ground temperature at the weather site (degrees Celsius) |
The weather file window will also display the hourly weather data for a single day in graphical and tabular form. The day displayed can be changed by entering a different value in the Day box, or by clicking on the arrows to scroll through the days.
Days are numbered from 1 to 365. The day numbers for the first day of each month and the number of days in each month are as follows:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
1 |
32 |
60 |
91 |
121 |
152 |
182 |
213 |
244 |
274 |
305 |
335 |
(31) |
(28) |
(31) |
(30) |
(31) |
(30) |
(31) |
(31) |
(30) |
(31) |
(30) |
(31) |
If the year begins on a Monday, then day numbers divisible by 7 will be Sundays:
Month |
Sundays |
Jan |
7,14,21,28 |
Feb |
35,42,49,56 |
Mar |
63,70,77,84 |
Apr |
91,98,105,112,119 |
May |
126,133,140,147 |
Jun |
154,161,168,175 |
Jul |
182,189,196,203 |
Aug |
210,217,224,231,238 |
Sep |
245,252,259,266,273 |
Oct |
280,287,294,301 |
Nov |
308,315,322,329 |
Dec |
336,343,350,357,364 |