Following the epidemic outbreak of COVID-19 in Wuhan, China, in December 2019 (1), most countries are currently in a pandemic situation. The behavior of this disease is extremely sophisticated and is the main topic of discussion in academic circles. The maps describing COVID-19 are being updated every day; however, almost all these maps have focused on the number of disease cases and the death number. At present, drawing maps and performing analyses based on other parameters such as latitude and socioeconomic factors could be useful for researchers and health policy-makers.
We employed the WHO report (2) as the main source of COVID-19 data based on the last update on April 2, 2020. Initially, the equator and the prime meridian were used for dividing the world into four parts: northeastern, northwestern, southeastern, and southwestern ( Fig. 1, a) . Based on primary COVID-19 data, two main variables of this study included the proportion of cases to population per 10 5 (PCP) and the proportion of death to population per 10 5 (PDP). Other parameters were the average temperature ( o C) and GDP ($US) of countries, which were extracted from different websites (3, 4). A descriptive analysis was performed on all the data.
Bivariate correlation and regression test were used to analyze the associations between socioeconomic and meteorological factors (temperature, GDP, latitude, and longitude) and the variables of COVID-19. Also, the scatter plot of log case and death rate with log GDP was drawn using SPSS. All the statistical analyses were performed at a 5% significance level.
The results showed that the majority of cases (533241) were observed in northeastern areas, the more COVID-19 PCP (43.26 per 10 5 people), were also appeared northeast. The pattern of PDP was similar to the case rate, and the highest death rate was found in the northeast (1.63 per 10 5 ).
Categorizing the COVID-19 case rate based on latitude revealed that this variable is associated with the COVID-19 latitude (r=0.54; p<001). As it appears in Fig. 1a (the highlighted line passing through the prime meridian), in the latitude beyond 60°, a higher PCP of COVID-19, 104.54 per 10 5 , is observed. Countries with a higher GDP had more COVID-19 PCP and PDP (Table 1 and Fig. 1b, c) . Furthermore, temperature had a reverse association with both COVID-19 PCP (r=-0.50; p<001) and PDP (r=-0.50; p<001). While discussions about the results of COVID-19 distribution throughout the globe are inconclusive, we suggest some possible reasons for these findings. Interestingly, higher COVID-19 PCP and PDP were observed in northern areas, including some parts of North America and approximately the entire Asia and Europe which are located in higher latitudes and have a colder climate and better socioeconomic condition. To interpret these results, the authors suggest some major reasons for these data. First, the distribution patterns and the mentioned associations could be related to the availability of diagnostics kits and health care facilities (5, 6) . In addition, both colder climate and more densely populated areas could contribute to the spread of the disease in European and Asian megacities (7, 8) .
Several studies have suggested that a higher temperature could be effective against different types of coronavirus such as SARS (9) (10) (11) . In the study by Ma et al. (2020) , it has been reported that there is a negative relationship between COVID-19 mortality and temperature (12) because at lower temperatures, the performance of the immune system, as well as the liver, is decreased; as a result, the situation will be conducive to the activity of infectious agents and virus transmission (13-17) . Furthermore, the mortality rate and incidence of COVID-19 could be associated with air pollution and the average age of the population. It seems that older populations in the northern hemisphere, especially in Europe and North America with a higher income, have a higher death rate from respiratory infections (18) (19) (20) (21) . Additionally, it seems that air pollution plays a determinative role in COVID-19 outbreak and mortality. For instance, dayby-day changes of pollutant concentration were positively linked with the number of infected individuals in Italy; likewise, the number of confirmed cases was extremely higher in cities with more than 100 days of air pollution than cities with cleaner air (22) . A substantial relationship has also been found between urban air pollution and the transmission dynamics of COVID-19. In addition, it has been established that air pollutants emitted from vehicles and industries, such as nitrogen oxide and particle matter, may affect viral infection emission and increase the number of hospital admissions due to respiratory virus bronchiolitis and asthma (23) (24) (25) (26) .
While it is still not well established in the case of the coronavirus disease, vitamin D deficiency in people living in high-latitude areas and colder climates may somehow trigger the disease in those regions (27) (28) (29) . Vitamin D supplementation is highly recommended for preventing acute distribution and mortality, including humidity, wind speed, and air pressure. Besides, government-based interactions such as compulsory quarantine, social distancing, and advertising precaution measures could bring substantial benefits to cope with COVID-19 in different areas.
We should also address intrinsic limitations and the fallacy of ecological research to some extent.
We believe that this study can provide researchers with a deeper understanding of the coronavirus distribution pattern and the associated contributing factors. It is also suggested that, in the future, studies address the effect of public awareness, social distancing, quarantine effectiveness, and people's participation in isolation plans.
The ethical approval or individual consent was not applicable.
All data and materials used in this study were publicly available and mention in the text.
Not applicable.