In the neutralization of HCl and NaOH i was instructed to measure the temperature of the acid HCl prior to mixing the reaction components. I was to assume however, that the NaOH solution was at this same temperature. Is this a reasonable assumption?

If you had them sitting next to each other for the time necessary to reach room T, probably so. Or if they both came from a common location (for example, the stock room), probably yes. Otherwise, no.