This study employed daily rainfall values of 10 meteorological stations in Anuradhapura, Vavuniya, Ampara, Kilinochchi and Mullaitivu districts covering Agro Ecological Regions (AER), DL1b, DL2a, DL2b, DL1e, DL1f and DL3. The methodology involved descriptive statistical techniques to derive yearly and monthly variations and probability calculations to derive frequency of dry spells. Incidence of consecutive wet weeks was analysed using Markov chain analysis. Except for Ampara, the rest of the locations analysed in this study recorded an average annual rainfall less than the minimum rainfall requirement for rubber. The AERs in the Dry zone are vulnerable to droughts especially during March to August. The chance of having long dry spells is less than 20% in all the sites during October, November and December. If cultural operations are carried out according to a proper plan the repercussions of drought conditions can be minimized to a considerable extent. Accordingly, holing operation which requires a moist soil should be done during 17th September to 30th September followed by planting during 22nd October to 04th November to catch the maximum possible length of the wet season to assure maximum establishment success. First, second and third fertilizer applications in the first year of planting need to be done during 17th to 31st December, 26th March to 8th April and 24th September to 7th October respectively, to avoid heavy rains and dry spells. It is inevitable to prevent any departures from these stipulated dates since, uncertainty stands as all these dates have been computed using the probability theory. Hence proper cultural operations and moisture management practices, viz. irrigation, mulching and intercropping throughout the immature phase of rubber are of great importance to assure a healthy rubber plantation with minimum vacancies and accepted growth rates.