The impact of climate change and fluctuations in the production of agricultural products can affect food security. Rice, as a critical grain product in the north of Iran and especially in Mazandaran province, is also affected by these factors. This study was done to investigate the impact of climate change on the rice crop calendar. In this study, changes in climate variables were extracted based on CMIP6 models under the SSP scenario from 2021 to 2050 and compared to the base period (1985–2014) in different phonological stages. The results of the evaluation of observational and simulated data by linear scale bias correction (LSBC) show that the model accuracy differs in different stations. So that the highest and lowest accuracy of precipitation is between 4.3 and 12 mm, relative humidity between 1 and 3%, wind speed 0.1–0.2 m/s, maximum temperature between 0.1 and 0.9 °C, average temperature between 0.1 and 0. 7 °C, and the minimum temperature is between 0.1 and 0.5 °C, which indicates the high accuracy of this model. The prediction of climatic variables showed that the maximum, minimum, and average temperature, precipitation, and relative humidity in different stages of rice phenology will have significant changes in the future climate under the SSP scenario. The forecasting results of climatic variables show different behavior in phonological stages, so that, in SSP1-2.6 and SSP3-7.0 scenarios, mainly decreasing changes and SSP5-8.5 scenarios mainly increasing precipitation will occur. Meanwhile, changes in wind speed in all phonological stages and the entire growth period in future scenarios will not have significant changes compared to the base period; however, the significant increase of temperature variables will be evident in all phonological stages and scenarios compared to the base period, especially in the SSP5-8.5 scenario. Also, changing the planting date will change the length of the growth period and the amount of precipitation.

气候变化的影响和农产品生产的波动会影响粮食安全。大米作为伊朗北部特别是马赞德兰省的重要粮食产品，也受到这些因素的影响。这项研究的目的是调查气候变化对水稻作物日历的影响。本研究基于CMIP6模型提取了SSP情景下2021年至2050年的气候变量变化，并与基期（1985年至2014年）不同物候阶段进行比较。通过线性尺度偏差校正（LSBC）对观测数据和模拟数据的评估结果表明，不同站点的模型精度存在差异。使降水量的最高和最低精度在4.3～12mm之间，相对湿度在1～3%之间，风速在0.1～0.2m/s之间，最高温度在0.1~0.9℃之间，平均温度在0.1~0. 7℃之间，最低温度在0.1~0.5℃之间，表明该模型的精度较高。气候变量预测表明，SSP情景下，水稻物候不同阶段的最高、最低、平均气温、降水量、相对湿度将对未来气候产生显着变化。气候变量的预报结果在物候阶段表现出不同的行为，因此，在SSP1-2.6和SSP3-7.0情景中，主要发生降水变化，SSP5-8.5情景主要发生降水增加。同时，未来情景下各物候阶段和整个生育期的风速变化较基期不会发生明显变化；然而，与基期相比，所有物候阶段和情景中温度变量的显着增加都将是明显的，特别是在SSP5-8.5情景中。此外，改变种植日期也会改变生长期的长度和降水量。