Mountaineering Scotland said high mountains still have substantial snowfields and snow patches are lying across routes up many popular hills.
Temperatures have been unseasonably low, with new snow falling on some of the higher mountain tops.
Experts warned much of the old snow people encounter may be hard and icy, posing a “significant threat” to anyone not properly equipped.
Heather Morning, mountain safety adviser with Mountaineering Scotland, said: “Every year at this time, folk get into difficulties when encountering old snow patches.
“Sadly, a slip and subsequent slide in the wrong place does sometimes result in fatalities.”
Ms Morning advised walkers who do not have the kit or knowledge to deal with hard snow to adjust their plans and head to the lower hills or glens.
She added: “If you are planning to head up onto the higher mountains, take a good look at the mountain weather forecasts.
“If temperatures at 900m are forecast to be below freezing then my advice would be to still have your winter kit with you - a rigid pair of boots, crampons and an ice axe.”
Carey Davies, hillwalking development officer at the British Mountaineering Council, said there can be a big difference in climatic conditions across Britain.
He said: “When spring arrives, a lot of people feel the pull of the mountains and want to get up high again.
“But don’t forget to check the weather forecast carefully and be prepared for things like snow fields and cornices.”