Agricultural production is an important sector for peoples to live but it is highly affected by climate change and requires good understanging of each climatic parameters. Hamelmalo, the study region is vulnerable to climate change which is realized by total production loss but there is no concrete reference due to lack of data for long time. However, in 2015, a meteorological station was established and one of the objectives of this study was to evaluate the available climatic parameters by comparing the observed value with expected value from local climate estimator model with chi square test for the year (2015-2019). Based on the result, all climatic parameters under test except precipitation were almost in par with the values from the model (LCE), which means no significant difference and from this we can understand that the most variable climatic parameter in Hamelmalo is precipitation. Generally precipitation shows average increment but not linearly which is unreliable and based on the ten years of precipitation record, annual precipitation is 445 ±23.9 mm with 2015 has lowest and 2019 has highest precipitation records. The region has mild climate and May is the hottest month and high PET but August is the month with lowest sunshine hours and PET and highest precipitation. Mean monthly relative humidity for all the month is above 70% excepte for May and June. PET decreases linearly from 2015-2019 and both PET and precipitation affects the climatic water balance of Hamelmalo with the most influencial is precipitation. Since precipitation is variable, CWB is also variable with the highest varibility in the month of July. There is no variation in CWB in Hamelmalo during non rain season. Since rain start from June variation in CWB also starts from this month but the varation is not much especially from mid of the month due to less varation in precipitation. The same in August with high precipitation, and high cumulative CWB, the varation is not much and it is positive CWB with most reliable for plant growth. Temperature also contribution in CWB decrease as it affects PET especially in 2016 with the hottest year in the world. Nevertheless changes in the CWB, as a reaction to changes in P and ET, have not yet been tested carefully in many parts of the world, including Eritrea. This analysis shows that the annual cumulative CWB in Hamelmalo was negative due to 67% of the year is dry season without precipitation leads to negative CWB and based on the study 2015 has the highest potential evapotranspiration and lowest precipitation and this causes lowest climatic water balance in the that year opposite to this 2019 has lowest potential evapotranspiration and highest precipitation and leads to higher climatic water balance. However, the value of climatic water balance for each month does not depend on the total precipitation or evapotranspiration, but it depends on the precipitation and evapotranspiration of individual months. The aim of this study was also to estimate the crop and irrigation water requirements on sorghum cultivation in Hamelmalo, Eritrea and Climate data from 2015–2019 were obtained from the weather station at the Hamelmalo Agricultural College (HAC), Hamelmalo. The CROPWAT model 8.0 was then used to determine the rate of reference evapotranspiration (ETo), effective rain fall, evapotranspiration of sorghum (ETc) and irrigation water requirements (IWR) in Hamelmalo, Eritrea. The results showed that the annual ETo from 2015-2019 at the station was 1641.72 mm and the total effective rainfall was 389.7 mm out of 472.9 mm received during this period, representing 82.4% of the rain received. Based on the result, the total sorghum evapotranspiration rate (ETc) from 2015-2019 was measured as 391.3 mm/ growing season when sowing time was 1st of July and 390 mm/growing season when sowing time was 20th of June. The irrigation requirement was measured as 181.6 mm/ growing season when sowing time was 1st of July and 134.6 mm/ growing season when sowing time was 20th of June. additionally, high yield decline are expected in the mid and late developmental stages because the mid and late developmental stages require more water than other stages especially during mid-season stage water is highly important. Given the low and highly variable precipitation in Hamelmalo, Eritrea, much enough yields will only be realized if additional irrigation water is supplied. It is therefore highly recommended that changing planting dates to meet with the needed precipitation should put in to account. Sowing earlier in June is much better than in July and also allocating water to the most critical crop developmental stages which would help to maximise yield.