http://www.visitscotland.com/guide/where-to-go/geography/climate/

The wetter months tend to be in the autumn.
December and January can often be very nice with cold dry days, perhaps with a little snow on the ground.
May is often very good with warm dry spells, but July and August often alternate heavy rain with warm sun!
Summery periods with high temperatures occur sometime from June to September, though exactly when is ..????????.

The dreaded midges generally arrive from early June, but are mostly all gone by mid August. That said, they only fly if the wind speed is less than 4 mph, and generally only early in the morning and at dusk.   On the whole, from 0900 to 1800(ish), they are grounded and are fairly unnoticeable.

In summer, daylight lasts from 0300 till 2200, but in mid winter it’s dark till 9 am, and dusk starts at 3.30pm!

For a forecast of the weather in Strathclyde visit:

www.metoffice.gov.uk/weather/uk/st/st_
forecast_weather.html

or for the BBC:

What is the weather going to be like on my holiday?