Map from Google - Liechtenstein

The climate of Liechtenstein is continental at low altitude, while it's Alpine in the mountains. Liechtenstein is a small country of 160 square kilometres (60 square miles), located between Austria and Switzerland. The capital Vaduz is situated in the Rhine Valley, at 450 metres (1,450 ft) above sea level. The eastern part of the country is mountainous, the highest peak is Grauspitz, 2,600 metres (8,500 ft) high.

The climate is continental in Vaduz and in the valley, so it's cold in winter, with an average in January around freezing (0 °C or 32 °F), and relatively warm in summer, with a maximum average around 23/24 °C (73/75 °F) in July and August.
Here are the average temperatures of Vaduz.
Average temperatures - Vaduz
Min (°C)-3-22581214131172-1
Max (°C)35111418212423201585
Min (°F)272836414654575552453630
Max (°F)374152576470757368594641

In winter, from December to February, cloudy and dull days are frequent, accompanied by rain or snow, typically light but continuous. Sometimes, while in the valley the sky is overcast, the sun shines high in the mountains. Outbreaks of polar air masses of Siberian origin can bring glacial weather, with minimum and maximum temperatures below freezing even in the valleys.
During summer, from June to August, periods of good weather can be hot in the valley floor, which can be interrupted in the afternoon or evening by thunderstorms, sometimes intense.
The southerly wind, the warm and dry Föhn, is more frequent in autumn, and can lead to sudden increases in temperature.
The average annual precipitation is around 950 mm (37.5 in) in Vaduz, with a maximum in July, August and September because of thunderstorms. In the other months of the year, the rains are quite frequent, due to the Atlantic fronts, but are rarely abundant. In winter, precipitation often occurs in the form of snow.
Here is the average precipitation in Vaduz.
Average precipitation - Vaduz
Prec. (mm)555545507090115125120907070955

In the high mountains, where the climate is colder and windier, snowfalls can occur for a longer period, depending on altitude. In the mountains, precipitation is more abundant and exceeds 2,000 mm (79 in) per year: the abundant winter snowfalls are replaced by the strong summer thunderstorms.

Vaduz Castle

When to go

The best time to visit Liechtenstein runs from mid-May to late September, when the weather is mild or pleasantly warm during the day, but cool at night in the valley (and even cold in the mountains); there can be some cool and rainy days, and afternoon thunderstorms are likely, especially in the mountains.

What to pack

In winter: warm clothes, hat, down jacket, scarf, gloves, raincoat or umbrella.
In summer: clothes for spring and autumn, t-shirts, but also long pants, jacket, sweatshirt or sweater for the evening and cooler days; raincoat or umbrella. For the mountains, sweater, jacket, hiking shoes, sunscreen and sunglasses.