Thanks Nick.My darkroom is in my basement,the temperature is the same year
round.

I have news for you.  RA-4 paper is a thin emulsion paper that is
developed essentially to completion.  For that reason, the instructions
with the RA-4 kits say that 50% over-development is acceptable. This can
be translated into a certain number of degrees of higher than nominal
temperature for the development time.

I have been using the Jobo (Tetenal) room-temperature kit for years. I
put a thermometer in the tray, determine the development time from that
temperature, and make sure that the paper gets at least that much time
in the developer.  It usually is a time between 50 and 70 seconds. I
don't worry about ten seconds extra.

To demonstrate that this gives consistent results, I will say that a
number of times I wanted to make a new print of a negative that I had
printed years before, and had no difficulty getting an identical print.

If it is not obvious from the above, I should tell you that I do RA-4 in
trays, just as it it were black and white. After all, the only total
darkness step is development and the first twenty seconds in the stop
bath. After that, I can turn on the lights. Using drums for RA-4 is just
a colossal waste of time. I might have some sympathy for the relatively
expensive Jobo processors; allegedly they could speed up mass production
printing, but  not having had any direct experience with them, I can't
say.