AdrianKMFYes, these are fine in the summer. They'll keep the mozzies from biting you, though they do get a bit warm but I just open the fly to vent as I'm walking. A better summer option is the Keb Trousers (imo, get the regular, I had the gaiter version and never used the feature.) The Kebs have stretch paneling so clambering over stuff or steep inclines are much more comfortable. That and they have ventilation zips on the thigh and calf. My only warning is the stretch panels don't stop mosquitos that well.
If you're walking on the flats, these are excellent. Especially when paired with some knee pad inserts so you can stop and kneel in comfort.
BradyI second the Keb's, if you're actually planning to hike. I mostly keep my Vidda pro's for various work and sometimes casual use. They're pretty durable, fit great and have really useful pockets, but they're not very weatherproof or breathable, and pretty heavy. There are so many, so much better options for hiking.
Please advice.