I've found I've really become dependant on roads and cold.
Last month or so I've started running in afternoons rather than strictly 7am. I'm reaching 10-15 degrees more in terms of temps and I've also hit the off-road runs on fields and also down by the river Mersey (Chorlton/Didsbury way). Went out in 24c down near river (stones/sand/mud/grass) and I stopped at 5k mark (despite the fact I've been doing 10ks for over a year now). Felt not right after I took a steep flight of steps to get off the Mersey trail (something I've never had to do with road running).
I know it's doing me good to switch up. If I don't and decide to say Manchester 10k event and it gets hot I need to prepped or if I decide to eventually do Tatton I need a varied run plan.