Dunedin Local Knowledge for Outdoor Property Care

• Prevailing winds: mainly southwesterlies; late‑spring northeasterlies; occasional warm, dry northwest foehn winds (National Institute of Water and Atmospheric Research - NIWA).

• Shelter: a ring of hills around the inner city reduces the direct impact of weather; central basins and valleys remain comparatively milder.

• Exposed areas: oceanfront suburbs of St Clair and St Kilda; Otago Peninsula towns (Portobello, Macandrew Bay, Broad Bay); West Harbour (St Leonards, Port Chalmers); Taiaroa Head.

• Sheltered pockets: inner harbour and nearby valleys (e.g., North East Valley, City Rise, Roslyn facing the harbour).

• Practical care: select salt‑tolerant, wind-hardy plantings; install layered windbreaks; brace young trees; mulch to reduce moisture loss; and schedule hedge cuts during calmer periods.

• Why it matters: Plant selection and timing of maintenance play a key role in protecting turf, shrubs, and hedges from ongoing wind and salt exposure.

• Frosts: about 49 frost days per year city‑wide (lower than many South Island centres).

• Snow is uncommon in the city; however, a few snowy days occur in higher suburbs, such as Halfway Bush and Wakari.

• Temperature norms (NIWA): mean daily maximum roughly 14.9 °C; mean daily minimum around 7.5 °C in winter; annual mean around 11.2 °C.

• Extremes (1947-present): record high 35.7 °C; record low -8.0 °C.

• Inland/hill effects: Taieri/Middlemarch is more sub‑continental - winters are cold and dry with fog; summers can reach around 30 °C.

• Elevation: inner hills around 200 m; peaks such as Mount Cargill (700 m) and Flagstaff (680 m) create cooler microclimates than coastal flats.

• Practical tips: raise mowing heights before frost, avoid overnight watering in winter, plan planting/fertilising around frost windows, consider frost cloths in frost‑prone hollows, and choose varieties suited to coastal vs. inland sites.

• Annual rainfall: about 724 mm.

• Monthly pattern: many months around 52 to 71 mm; October can be drier, around the mid-50s; heavy downpours are less common.

• Rain days: around 105 to 110 days per year, supporting steady growth but requiring moss and shade management in damp areas.

• Terrain influences: dunes near South Dunedin beaches improve drainage in some zones; steep valley sides drain quickly, while reclaimed flat areas may pond during wet spells.

• Subsoil and soil notes: Coastal soils near the harbour may be lighter and more sandy, with shading and wind reducing moisture retention.

• Practical actions: core aeration on compacted lawns, topdressing to improve infiltration, thatch control, and ensuring green waste is removed to approved facilities to protect soil health.

• Sunshine: roughly 1,775-1,850 hours per year (NIWA data varies by site).

• Seasonal spread: mid-summer months, each around 165 to 185 hours; mid-winter, around 96 to 115 hours. Expect slower growth and more shade and moisture in winter.

• Aspect effects: north‑facing slopes are warmer/drier and boost growth; south‑facing slopes stay cooler/damper - higher moss and fungus risk.

• Hill shade: inner hills (approximately 200 m) and higher peaks (e.g., Signal Hill, Saddle Hill) create localised shade and cooler microclimates.

• Maintenance moves: raise mowing heights in shade, prune for light penetration, select shade‑tolerant turf/groundcovers, and schedule hedge work to avoid peak UV/wind stress on exposed faces.

• Spring (September to November): rapid flush; northeasterlies can alternate with cool SW changes, fortnightly mowing often shifts to weekly on warmer, sheltered sites.

• Summer (December to February): mild, with peaks reaching 30+ °C at times; coastal wind/salt stress rises; irrigate deeply but less often; maintain mulch; and time hedge shaping for recovery windows.

• Autumn (March to May): key recovery and renovation window, core aerate, topdress, and fertilise as soils cool but remain workable.

• Winter (June to August): cool, relatively sunny by South Island standards; inland Taieri can have freezing fogs, extend mowing intervals, manage moss in shade, and protect frost‑tender species in valleys/hollows.

• Frequency guide: wind‑exposed coastal/peninsula sites benefit from wind‑hardy planting and seasonal staking; higher suburbs may need frost cloths and modified fertiliser timing; central, sheltered basins often enjoy steadier, year‑round turf growth.

• Property‑wide planning: align hedge clearances with council standards (2.5 m over footpaths; 4.5 m over roads; 500 mm kerb setbacks), select salt‑ and frost‑tolerant plants by zone, and match service cadence (weekly/fortnightly/monthly) to your microclimate.

For more information, refer to the following link:

• Dunedin Climate and Local Conditions (Dunedin City - Wikipedia)