During my visit in June of 2016, I met some very nice people from Iceland. They recommended coming back to Iceland in October for seeing the Northern Lights. They gave two reasons: the weather is not too bad (there is usually not much snow at that time) and there is enough darkness. In order to increase the chance of darkness I chose 6 days to be around a new moon. The sun will rise around 7:30 and set around 18:00; so if the sun does not oblige the days of my visits with a lot of activity I can shoot both sunrises and sunsets.
Of course, there is a good chance I will see a lot of rain. When I was there in May of 2014 my friend and I saw rain 8 of the 10 days we were there. But the scenery is so spectacular...and the weather changes so fast, we were still able to capture some wonderful images. I love black and white and stormy weather can create a wide gamut of tones. Of course, having very good clothes to be comfortable is critical to focusing on one's art...and not how cold or wet it is.
The reading about auroras is very interesting; there are plenty of websites with succinct information. I learned about the solar cycle, which lasts approximately 11 years. (The cycle we are in now began around 2012.) It is measured by the amount of solar activity. The cycle we are currently in is regarded as a relatively weak cycle. The bottom line is the particles produced by solar activity pass through the Earth's magnetic poles (north and south) and mix with the atmosphere's particles. Collisions with oxygen particles emit yellows and greens; with nitrogen particles red, violet and sometimes blue. One has a higher probability of seeing an aurora the closer one is to one of the two poles in darkness.
In order to simplify our search for auroras there is a KP index (see www.aurora-service.eu ). On that site there is a map showing what the minimum index needs to be in order to have a chance to see an aurora in your area. According to their map southern Iceland requires an index of KP3 (the index goes from 0 to 9). The higher the KP index the further south an aurora can be seen (in the northern hemisphere). However, you can have an extremely high KP index (>KP5) on a night, but if there is cloud cover no aurora.
I have found two very good apps to help my hunt: Aurora Pro and Aurora Forecast. My preference is Aurora Pro. In a nutshell its forecast page is divided in two: "Forecasts" gives you the Viewing probability in percent; the Cloud Coverage; the next hour's realistic KP index and upcoming days KP index. "Solar Winds" gives you wind speeds (we want high speeds); wind density (we want more density); Solar wind Bz, is the measurement of the interplanetary magnetic field, which we want to be a negative number (see www.auroranotify.com ), which means the magnetic field is tilting south. The more it tilts south the higher the probability and higher KP index.
Just in case there is not enough solar activity or clear skies I am planning to spend a lot of time at two beautiful water falls, Seljalandsfoss and Skógafoss, the black beaches of Vik, Reynisfjara basalt rocks, Dyrhólaey, and Kirkjufjara beach. Weather permitting I may try to reach the canyon of Fjadrárgljúfur, Svartifoss waterfall in Skaftafell National Park.
Since I have been to Vik (and many of the sites around that area) before I can plan a lot of my shots. I highly recommend another app, PhotoPills, to help plan your shots. Its "Planner" section allows you to drop a pin in the spot you want to shoot and see the exact position of the sun during the day and the milky way at night. The month before I went back to Kirkjufell mountain in 2016 I would have dreams of the images I wanted to take, the placement of my tripod, and the different exposure times. More on specific preparation of my images for the upcoming trip to Vik in my next blog.