A Lacoste-Romberg gravimeter was observed to exhibit abnormal drifts of varying character and magnitude when employed for field surveys under the Nigerian tropical heat. The gravimeter was therefore observed under specific instrumental and climatic conditions at a fixed location in Jos, Nigeria, in order to ascertain the nature of the abnormal drifts especially those influenced by temperature changes around the instrument. We found that temperature conditions affected both the drift and the sensitivity in such a manner that suggested that the temperature compensation of the instrument was inadequate possibly due to aging. The effect was the introduction of errors ranging between 10^-3 mGals to 10^-2 mGals. Given the cost of new instruments and the problems often associated with the repair of aging ones, we recommend that more compensation must be sought in addition to a measurement procedure that would enhance meter stability in order to improve the reliability of aging gravimeters in the tropics.