Humidity - yet again

I live in Brisbane which has a semi tropical climate similar to that of Hawaii. Right now relative humidity on the Big Island is 74% here it is 60%. Meteorologcal statistics state that Brisbane's humidity ranges between 60 and 71. The fact that my hydrometers measured 80% last week is, apparently insignificant and it must be said that humidity changes within short geographical distances. I have an analogue hydrometer in the room I keep my ukes and a digital Caliber III in each uke case. There is an analogue temp and hydrometer as a fixed feature in one of my cases but it is worse than useless. Right now it is reading 50% whereas the caliber III, in the same case, is reading 60%. My analogue and digital hydrometers consistently read the same but for accuracy I would go the digital route every time. (this goes against the grain because I am an anologue person who still uses turntables, vinyl, reel to reel and cassette recorders in preference to CD's and MP3 players),
Am I being over cautious by having three Herco's and packets of silicagel situated in the same room as my ukes - in case of emergency, when I have had a 1959, arch top, Hoyer guitar, spruce soundboard and maple body, on a stand for the past 20 years with no ill effects due to humidity?
Cheers
Tred

Aloha Tred:
I wouldn't tell you otherwise,,,don't wan't to feel liable if anything goes wrong... check and ask around your area it anyone has problems there, first place is probally the music shops...Good Luck!! MM Stan..

If it only varies 10-15% I wouldn't worry... Where I live (Ohio, US) we get probably a 75% swing over the course of a year

Hello from Cairns. The humidity here is worse than there in Brisbane. Here, ideally, most of the year you need a dehumidifier in your case, or keep your instruments a climate / humidity controlled cupboard / room. M.U.D. dehumidifiers (for in your case) are fantastic (we sell them in our shop all the time). Silica gel packets are not very good as once they have absorbed moisture, they are useless, unless you have some way of recycling them. Herco's are humidifiers, so I am not sure why you'd need them with humidity being over 60%?

You can also buy dehumidifiers that you can place in a room or cupboard that suck humidity out of the air. That may be something you could look at, to cover the extremes, especially now that we are going into the wet season.

Thanks for the input. Much of the confusion has been resolved and I will try and keep the humidity between 50 and 70% - ideal 60%. The reason for the Herco's, Gaby, is that when the westerlies blow in winter humidity drops way down. I admit I am overcautious about this and panic when I see sites such as Taylor Guitars where they recommend to keep humidity between 45 and 55%.
Cheers
Tred

Taylor recommendations are based on the fact that is is very possible in a house where central heat runs constantly that you could end up in the 20s! As long as you don't get below 40% inside your house, you don't need to worry.