BACKGROUND: To estimate a possible association between the effects of daily meteorological variation and climatological changes (temperature, air pressure, humidity, sunniness level) on pregnant women with hyperemesis gravidarum (HG) according to symptoms grade and hospitalization state. METHODS: A retrospective study was conducted with 118 patients diagnosed and hospitalized with HG. HG patients were graded as mild, moderate, or severe according to the Pregnancy Unique Quantification of Emesis (PUQE-24) scale. Data regarding demographic characteristics, PUQE scale value, gestational week on hospitalization, hospital admission and discharge dates, weather conditions, daily meteorological values during hospitalization ( temperature, air pressure, humidity, sunniness level), seasonal averages, and daily changes were recorded. Weather records were obtained from the Ankara Meteorology General Directorate (Ankara, Turkey). Differences between groups were compared according to HG grade. RESULTS: HG cases were classified as mild (33.1%), moderate (44.9%), or severe (22.0%). The number of hospitalization days significantly differed between these three groups (p<0.05). In contrast, no statistically significant differences were identified between the HG grade level groups in regard to humidity, pressure, temperature, and sunniness level data (p>0.05). In addition, no statistically significant relationship was identified between HG grades and seasonal conditions according to the chi-square test (p>0.05). CONCLUSION: Changes in the meteorological and climate values examined were independent of symptom severity and hospitalization rate for our HG patients. However, it is possible that climate changes occurring around the world may affect the pregnancy period and should be further investigated.