2350 running to hot

[Mudflap77]

My 2350 heats up pretty quick on any kind of pull, either getting up to speed or pulling a hill. The fan has no trouble keeping it cool and it's not over heating. But the temp climbs to 210 pretty quick the fan pulls it down to 200 shuts off and climbs right back up to 210 again in no time. Oil temp will get up to 235 if pulling up a longer grade. I've been blaming it on the hot weather. Is it common for a ISX operating temperature to climb quickly?
Isx 485 in a 579 Pete not modified about 720 000mi, I've put about 65 000mi on it. I realize the modern engines put a lot more demand on cooling system just seem like it might be abnormal.