It's not safe to ski, perhaps, between mid-March and the end of July (5)
I believe the answer is:
risky
'it's not safe' is the definition.
I can't tell whether this definition defines the answer.
'ski perhaps between mid-march and the end of july' is the wordplay.
'perhaps' indicates anagramming the letters.
'between' means one lot of letters goes inside another.
'mid' says to take the centre (mid- can mean the middle of something).
'and' says to put letters next to each other.
'the end of' suggests the final letters.
The centre of 'march' is 'r'.
The final letter of 'july' is 'y'.
'ski' is an anagram of 'isk'.
'r'+'y'='ry'
'isk' going within 'ry' is 'RISKY'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for risky that I've seen before include "Involving a chance of danger" , "not playing safe" , "Unsafe" , "taking a chance" , "Having possibility of danger or loss" .)