A drought is a disaster that poses great threats to maize production. Thus, it is vital to study the spatiotemporal evolution of the standardized precipitation evapotranspiration index (SPEI) in the maize-growing regions in Northeast China (MGRNC). Here, we use the meteorological data of each growth stage from 1961 to 2017. This work aimed to analyze the spatiotemporal variation characteristics of the SPEI in MGRNC using the Mann–Kendall (MK) trend test, MK mutation point test, and Morlet wavelet method. The results indicated that from 1961 to 2017, the average SPEI values in Liaoning and Eastern Inner Mongolia showed a downward trend (the linear trend rates were − 0.02/10a and − 0.04/10a, respectively); however, no clear trend was observed in SPEI values in Heilongjiang and Jilin. There was a main cycle of approximately 20 a and a subcycle of approximately 7–10a for SPEI values in the whole growth stage and the sowing–seedling stage in MGRNC from 1961 to 2017, while the SPEI changes in the other three growth stages were inconsistent with the whole growth stage. The spatial distribution pattern of SPEI values decreased obviously from northeast to southwest during the whole growing stage. The drought frequencies during the different growth stages indicated that it was relatively dry at the heading–flowering stage. With the development of the growth stage, the frequency of droughts decreased significantly. The values of drought frequency and relative drought area for each sub-region in the study area occurred in the following order: Eastern Inner Mongolia > Jilin > Liaoning > Heilongjiang. The frequencies of mild to moderate droughts were 48.16%, 39.08%, 38.41%, and 37.3%, respectively. Identifying the spatiotemporal pattern of droughts in maize areas can provide scientific information for decision-makers to form strategies to withstand droughts and prevent disasters.

干旱是对玉米生产造成极大威胁的灾害。因此，研究东北玉米种植区标准化降水蒸散指数（SPEI）的时空演变至关重要。这里，我们使用1961年至2017年各生长阶段的气象数据。本工作旨在利用Mann-Kendall（MK）趋势检验、MK突变点检验和Morlet小波方法分析MGRNC SPEI的时空变化特征。结果表明，1961年至2017年，辽宁省和内蒙古东部地区的SPEI平均值呈下降趋势（线性趋势率分别为-0.02/10a和-0.04/10a）；然而，黑龙江和吉林的SPEI值没有观察到明显的趋势。1961—2017年MGRNC全生育期和播苗期SPEI值存在一个约20 a的主周期和约7~10 a的次周期，而其他3个生育阶段的SPEI变化不一致与整个生长阶段。整个生育期SPEI值空间分布格局由东北向西南明显递减。不同生育期的干旱频率表明抽穗开花期相对干旱。随着生育期的发展，干旱发生的频率明显减少。研究区各分区干旱频率和相对干旱面积的大小顺序为：内蒙古东部>吉林>辽宁>黑龙江。轻中度干旱发生频率分别为48.16%、39.08%、38.41%和37.3%。识别玉米区干旱的时空格局，可以为决策者制定抗旱防灾策略提供科学信息。