On TNRPG, each major country experiences weather conditions. When you create a topic in a country, the weather conditions of your topic will mirror the weather conditions of your country when that topic is created. Every twenty-four hours, new weather conditions will be generated for each country, but this does not mean that the weather of in-progress topics will change.
In regards to two topics that would conflict with weather timing (Person A in a sunny training field, is met by Person B meeting up with them, with B coming from a topic where it was raining), the newer topic would have priority. If A's topic was newer, the rain from B's topic would have cleared away by then. If B's topic was newer, the rain would inevitably drift into B's topic.
You can find the weather statistics of each county on the bottom of the home page, above the Discord chatbox. There is also a link to a page where one can view all countries' weather at once, just below the main banner.