Someone collected a bunch of weather data years ago and graphed it here
(click to make bigger)
If you check the vanadiel time of year using /clock , and refer to the chart, you can see that the jungle is actually the best time of year around august.
Back when I unlocked smn ages ago i would zone between the 2 jungles every 5mins.
If its not during the summer months, just pop between the altepa zones instead.
Weather npc is also good to check too before you do a 2-3hr span of weather camping.