I get access to a Met Office Forecaster every day, and i have asked him what the weather is likely to be on Sun in the midlands.
He reckons, quite breezy and bright start, so it will be cold, with a NE wind. So expect a bit of wind chill. it will be cold out of the wind, and this will be increased to somewhere below freeezing in the wind, so the Intake temps will be ok!
The big one - rain - He does not think so. Reckons it will start fairly clear skied, and gradually build as the day extends. To medium level cloud, so not rain threatening. He does not expect any rain until Mon/Tuesday.
So take a umbrella, and a rain coat! Usually they are pretty good. I will get a detailed forecast on Friday morning, during our daily flying brief.