My temperature fluctuates – why, and what can I do about this?

The basal body temperature fluctuates daily, some days more than others. Changes in behavior can cause fluctuations as well – for example, change in sleep, travel, and sickness can cause the basal body temperature to fluctuate. This can cause Natural Cycles algorithm to take longer to understand where you are in your cycle.
The app will indicate that you have "fluctuating temperatures" if it has a hard time finding your ovulation day, due to a large spread among your temperatures.
The app may warn you about a very high or low value every now and then as well, remember to take these messages seriously – it's the app trying to help you.

Under Statistics in your app, the app may show you "problematic" under your standard temperatures and deviations for the cycle. If it shows "problematic", you need to check your graph to see which temperatures fluctuates and needs to be marked as
deviating temperature.

If you’re working shifts
If you're working odd hour jobs, for example if you usually work two nights per week, we recommend you to measure five days within the same time frame and skip the days you work nights. Then, measure the first day after switching to daytime. Try to measure within the same time frame (+-2 hours timeframe), as soon as you wake up.

If you’re taking care of a baby
If you have a baby and need to wake up during the night often, we do recommend you to measure after your longest stretch of sleep, or at least three hours of sleep. Read more.

If you travel within different time zones and/or to a different climate, skip measuring for 1-2 day/-s so that your body gets used to the temperature change and then measure as usual. Read more.

Do you have very few data points?
If you have a few data points (such as when you've just started with Natural Cycles) and believe that your temperature fluctuates, keep measuring until you complete one cycle of measuring and adding data. A cycle begins on the first day of menstruation and ends when your next menstruation begins, and the app will show you each cycle individually on the graph. The graph is the best place to spot a fluctuation on. You will clearly see what is a fluctuation and what’s not.

You should mark fluctuating temperatures as deviating, which will give you better statistics and also help the algorithm confirm ovulation. You can easily do this by clicking on the value on the graph, through the history view, or by clicking on the date in the monthly view.

Are you measuring in the right way?
Always measure before you get out of bed, as soon as you wake up. Read more.